Class Collection<Key, Value>

A Map with additional utility methods. This is used throughout discord.js rather than Arrays for anything that has an ID, for significantly improved performance and ease-of-use.

Type Parameters

Key
The key type this collection holds
Value
The value type this collection holds

Hierarchy

Map<Key, Value>
- Collection

Constructors

constructor

new Collection<Key, Value>(
entries?: null | readonly (readonly [Key, Value])[],
): Collection<Key, Value>
Type Parameters
- Key
- Value
Parameters
- Optionalentries: null | readonly (readonly [Key, Value])[]
Returns Collection<Key, Value>
Inherited from Map<Key, Value>.constructor
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:50
new Collection<Key, Value>(
iterable?: null | Iterable<readonly [Key, Value]>,
): Collection<Key, Value>
Type Parameters
- Key
- Value
Parameters
- Optionaliterable: null | Iterable<readonly [Key, Value]>
Returns Collection<Key, Value>
Inherited from Map<Key, Value>.constructor
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:49
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:50

Properties

`Readonly`[toStringTag]

"[toStringTag]": string

constructor

constructor: CollectionConstructor

The initial value of Object.prototype.constructor is the standard built-in Object constructor.

`Readonly`size

size: number

Returns

the number of elements in the Map.

`Static` `Readonly`[species]

"[species]": MapConstructor

Methods

[iterator]

"[iterator]"(): IterableIterator<[Key, Value]>
Returns an iterable of entries in the map.

Returns IterableIterator<[Key, Value]>
Inherited from Map.[iterator]
- Defined in node_modules/typescript/lib/lib.es2015.iterable.d.ts:119

at

at(index: number): undefined | Value
Identical to Array.at(). Returns the item at a given index, allowing for positive and negative integers. Negative integers count back from the last item in the collection.
Parameters
- index: number
  The index of the element to obtain
Returns undefined | Value
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:98

clear

clear(): void
Returns void
Inherited from Map.clear
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:20

clone

clone(): Collection<Key, Value>
Creates an identical shallow copy of this collection.

Returns Collection<Key, Value>
Example
```
const newColl = someColl.clone();
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:361

concat

concat(...collections: ReadonlyCollection<Key, Value>[]): Collection<Key, Value>
Combines this collection with others into a new collection. None of the source collections are modified.
Parameters
- ...collections: ReadonlyCollection<Key, Value>[]
  Collections to merge
Returns Collection<Key, Value>
Example
```
const newColl = someColl.concat(someOtherColl, anotherColl, ohBoyAColl);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:371

delete

delete(key: Key): boolean
Parameters
- key: Key
Returns boolean
true if an element in the Map existed and has been removed, or false if the element does not exist.
Inherited from Map.delete
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:24

difference

difference(other: ReadonlyCollection<Key, any>): Collection<Key, Value>
Returns a new collection containing the items where the key is present in this collection but not the other.
Parameters
- other: ReadonlyCollection<Key, any>
  The other Collection to filter against
Returns Collection<Key, Value>
Example
```
const col1 = new Collection([['a', 1], ['b', 2]]);
const col2 = new Collection([['a', 1], ['c', 3]]);
console.log(col1.difference(col2));
// => Collection { 'b' => 2 }
console.log(col2.difference(col1));
// => Collection { 'c' => 3 }
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:439

each

each(fn: (value: Value, key: Key, collection: this) => void): this
Identical to Map.forEach(), but returns the collection instead of undefined.
Parameters
- fn: (value: Value, key: Key, collection: this) => void
  Function to execute for each element
Returns this
Example
```
collection
 .each(user => console.log(user.username))
 .filter(user => user.bot)
 .each(user => console.log(user.username));
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:336
each<This>(
fn: (this: This, value: Value, key: Key, collection: this) => void,
thisArg: This,
): this
Identical to Map.forEach(), but returns the collection instead of undefined.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => void
  Function to execute for each element
- thisArg: This
  Value to use as this when executing the function
Returns this
Example
```
collection
 .each(user => console.log(user.username))
 .filter(user => user.bot)
 .each(user => console.log(user.username));
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:337

ensure

ensure(
key: Key,
defaultValueGenerator: (key: Key, collection: this) => Value,
): Value
Obtains the value of the given key if it exists, otherwise sets and returns the value provided by the default value generator.
Parameters
- key: Key
  The key to get if it exists, or set otherwise
- defaultValueGenerator: (key: Key, collection: this) => Value
  A function that generates the default value
Returns Value
Example
```
collection.ensure(guildId, () => defaultGuildConfig);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:41

entries

entries(): IterableIterator<[Key, Value]>
Returns an iterable of key, value pairs for every entry in the map.

Returns IterableIterator<[Key, Value]>
Inherited from Map.entries
- Defined in node_modules/typescript/lib/lib.es2015.iterable.d.ts:124

equals

equals(collection: ReadonlyCollection<Key, Value>): boolean
Checks if this collection shares identical items with another. This is different to checking for equality using equal-signs, because the collections may be different objects, but contain the same data.
Parameters
- collection: ReadonlyCollection<Key, Value>
  Collection to compare with
Returns boolean
Whether the collections have identical contents
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:380

every

every<NewKey>(
fn: (value: Value, key: Key, collection: this) => key is NewKey,
): this is Collection<NewKey, Value>
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
- NewKey
Parameters
- fn: (value: Value, key: Key, collection: this) => key is NewKey
  Function used to test (should return a boolean)
Returns this is Collection<NewKey, Value>
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:292
every<NewValue>(
fn: (value: Value, key: Key, collection: this) => value is NewValue,
): this is Collection<Key, NewValue>
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => value is NewValue
  Function used to test (should return a boolean)
Returns this is Collection<Key, NewValue>
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:293
every(fn: (value: Value, key: Key, collection: this) => unknown): boolean
Checks if all items passes a test. Identical in behavior to Array.every().
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
Returns boolean
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:294
every<This, NewKey>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => key is NewKey,
    thisArg: This,
): this is Collection<NewKey, Value>
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
- This
- NewKey
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => key is NewKey
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns this is Collection<NewKey, Value>
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:295
every<This, NewValue>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => value is NewValue,
    thisArg: This,
): this is Collection<Key, NewValue>
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => value is NewValue
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns this is Collection<Key, NewValue>
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:296
every<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): boolean
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns boolean
Example
```
collection.every(user => !user.bot);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:297

filter

filter<NewKey>(
fn: (value: Value, key: Key, collection: this) => key is NewKey,
): Collection<NewKey, Value>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
- NewKey
Parameters
- fn: (value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
Returns Collection<NewKey, Value>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:206
filter<NewValue>(
fn: (value: Value, key: Key, collection: this) => value is NewValue,
): Collection<Key, NewValue>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
Returns Collection<Key, NewValue>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:207
filter(
fn: (value: Value, key: Key, collection: this) => unknown,
): Collection<Key, Value>
Identical to Array.filter(), but returns a Collection instead of an Array.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
Returns Collection<Key, Value>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:208
filter<This, NewKey>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => key is NewKey,
    thisArg: This,
): Collection<NewKey, Value>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
- This
- NewKey
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns Collection<NewKey, Value>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:209
filter<This, NewValue>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => value is NewValue,
    thisArg: This,
): Collection<Key, NewValue>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns Collection<Key, NewValue>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:210
filter<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): Collection<Key, Value>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns Collection<Key, Value>
Example
```
collection.filter(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:211

find

find<NewValue>(
fn: (value: Value, key: Key, collection: this) => value is NewValue,
): undefined | NewValue
Searches for a single item where the given function returns a truthy value. This behaves like Array.find(). All collections used in Discord.js are mapped using their id property, and if you want to find by id you should use the get method. See MDN for details.
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
Returns undefined | NewValue
Example
```
collection.find(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:142
find(
fn: (value: Value, key: Key, collection: this) => unknown,
): undefined | Value
Searches for a single item where the given function returns a truthy value. This behaves like Array.find(). All collections used in Discord.js are mapped using their id property, and if you want to find by id you should use the get method. See MDN for details.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
Returns undefined | Value
Example
```
collection.find(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:143
find<This, NewValue>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => value is NewValue,
    thisArg: This,
): undefined | NewValue
Searches for a single item where the given function returns a truthy value. This behaves like Array.find(). All collections used in Discord.js are mapped using their id property, and if you want to find by id you should use the get method. See MDN for details.
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | NewValue
Example
```
collection.find(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:144
find<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): undefined | Value
Searches for a single item where the given function returns a truthy value. This behaves like Array.find(). All collections used in Discord.js are mapped using their id property, and if you want to find by id you should use the get method. See MDN for details.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | Value
Example
```
collection.find(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:145

findKey

findKey<NewKey>(
fn: (value: Value, key: Key, collection: this) => key is NewKey,
): undefined | NewKey
Searches for the key of a single item where the given function returns a truthy value. This behaves like Array.findIndex(), but returns the key rather than the positional index.
Type Parameters
- NewKey
Parameters
- fn: (value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
Returns undefined | NewKey
Example
```
collection.findKey(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:158
findKey(
fn: (value: Value, key: Key, collection: this) => unknown,
): undefined | Key
Searches for the key of a single item where the given function returns a truthy value. This behaves like Array.findIndex(), but returns the key rather than the positional index.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
Returns undefined | Key
Example
```
collection.findKey(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:159
findKey<This, NewKey>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => key is NewKey,
    thisArg: This,
): undefined | NewKey
Searches for the key of a single item where the given function returns a truthy value. This behaves like Array.findIndex(), but returns the key rather than the positional index.
Type Parameters
- This
- NewKey
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | NewKey
Example
```
collection.findKey(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:160
findKey<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): undefined | Key
Searches for the key of a single item where the given function returns a truthy value. This behaves like Array.findIndex(), but returns the key rather than the positional index.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | Key
Example
```
collection.findKey(user => user.username === 'Bob');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:161

findLast

findLast<NewValue>(
fn: (value: Value, key: Key, collection: this) => value is NewValue,
): undefined | NewValue
Searches for a last item where the given function returns a truthy value. This behaves like Array.findLast().
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
Returns undefined | NewValue
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:169
findLast(
fn: (value: Value, key: Key, collection: this) => unknown,
): undefined | Value
Searches for a last item where the given function returns a truthy value. This behaves like Array.findLast().
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
Returns undefined | Value
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:170
findLast<This, NewValue>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => value is NewValue,
    thisArg: This,
): undefined | NewValue
Searches for a last item where the given function returns a truthy value. This behaves like Array.findLast().
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => value is NewValue
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | NewValue
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:171
findLast<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): undefined | Value
Searches for a last item where the given function returns a truthy value. This behaves like Array.findLast().
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | Value
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:172

findLastKey

findLastKey<NewKey>(
fn: (value: Value, key: Key, collection: this) => key is NewKey,
): undefined | NewKey
Searches for the key of a last item where the given function returns a truthy value. This behaves like Array.findLastIndex(), but returns the key rather than the positional index.
Type Parameters
- NewKey
Parameters
- fn: (value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
Returns undefined | NewKey
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:181
findLastKey(
fn: (value: Value, key: Key, collection: this) => unknown,
): undefined | Key
Searches for the key of a last item where the given function returns a truthy value. This behaves like Array.findLastIndex(), but returns the key rather than the positional index.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
Returns undefined | Key
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:182
findLastKey<This, NewKey>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => key is NewKey,
    thisArg: This,
): undefined | NewKey
Searches for the key of a last item where the given function returns a truthy value. This behaves like Array.findLastIndex(), but returns the key rather than the positional index.
Type Parameters
- This
- NewKey
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => key is NewKey
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | NewKey
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:183
findLastKey<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): undefined | Key
Searches for the key of a last item where the given function returns a truthy value. This behaves like Array.findLastIndex(), but returns the key rather than the positional index.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  The function to test with (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns undefined | Key
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:184

first

first(): undefined | Value
Obtains the first value(s) in this collection.

Returns undefined | Value
A single value if no amount is provided or an array of values, starting from the end if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:62
first(amount: number): Value[]
Obtains the first value(s) in this collection.
Parameters
- amount: number
  Amount of values to obtain from the beginning
Returns Value[]
A single value if no amount is provided or an array of values, starting from the end if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:63

firstKey

firstKey(): undefined | Key
Obtains the first key(s) in this collection.

Returns undefined | Key
A single key if no amount is provided or an array of keys, starting from the end if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:71
firstKey(amount: number): Key[]
Obtains the first key(s) in this collection.
Parameters
- amount: number
  Amount of keys to obtain from the beginning
Returns Key[]
A single key if no amount is provided or an array of keys, starting from the end if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:72

flatMap

flatMap<NewValue>(
    fn: (
        value: Value,
        key: Key,
        collection: this,
    ) => Collection<Key, NewValue>,
): Collection<Key, NewValue>
Maps each item into a Collection, then joins the results into a single Collection. Identical in behavior to Array.flatMap().
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => Collection<Key, NewValue>
  Function that produces a new Collection
Returns Collection<Key, NewValue>
Example
```
collection.flatMap(guild => guild.members.cache);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:240
flatMap<NewValue, This>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => Collection<Key, NewValue>,
    thisArg: This,
): Collection<Key, NewValue>
Maps each item into a Collection, then joins the results into a single Collection. Identical in behavior to Array.flatMap().
Type Parameters
- NewValue
- This
Parameters
- fn: (
      this: This,
      value: Value,
      key: Key,
      collection: this,
  ) => Collection<Key, NewValue>
  Function that produces a new Collection
- thisArg: This
  Value to use as this when executing the function
Returns Collection<Key, NewValue>
Example
```
collection.flatMap(guild => guild.members.cache);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:241

forEach

forEach(
callbackfn: (value: Value, key: Key, map: Map<Key, Value>) => void,
thisArg?: any,
): void
Executes a provided function once per each key/value pair in the Map, in insertion order.
Parameters
- callbackfn: (value: Value, key: Key, map: Map<Key, Value>) => void
- OptionalthisArg: any
Returns void
Inherited from Map.forEach
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:28

get

get(key: Key): undefined | Value
Returns a specified element from the Map object. If the value that is associated to the provided key is an object, then you will get a reference to that object and any change made to that object will effectively modify it inside the Map.
Parameters
- key: Key
Returns undefined | Value
Returns the element associated with the specified key. If no element is associated with the specified key, undefined is returned.
Inherited from Map.get
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:33

has

has(key: Key): boolean
Parameters
- key: Key
Returns boolean
boolean indicating whether an element with the specified key exists or not.
Inherited from Map.has
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:37

hasAll

hasAll(...keys: Key[]): boolean
Checks if all of the elements exist in the collection.
Parameters
- ...keys: Key[]
  The keys of the elements to check for
Returns boolean
true if all of the elements exist, false if at least one does not exist.
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:48

hasAny

hasAny(...keys: Key[]): boolean
Checks if any of the elements exist in the collection.
Parameters
- ...keys: Key[]
  The keys of the elements to check for
Returns boolean
true if any of the elements exist, false if none exist.
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:55

intersection

intersection(other: ReadonlyCollection<Key, any>): Collection<Key, Value>
The intersection method returns a new collection containing the items where the key is present in both collections.
Parameters
- other: ReadonlyCollection<Key, any>
  The other Collection to filter against
Returns Collection<Key, Value>
Example
```
const col1 = new Collection([['a', 1], ['b', 2]]);
const col2 = new Collection([['a', 1], ['c', 3]]);
const intersection = col1.intersection(col2);
console.log(col1.intersection(col2));
// => Collection { 'a' => 1 }
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:407

keyAt

keyAt(index: number): undefined | Key
Identical to Array.at(). Returns the key at a given index, allowing for positive and negative integers. Negative integers count back from the last item in the collection.
Parameters
- index: number
  The index of the key to obtain
Returns undefined | Key
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:106

keys

keys(): IterableIterator<Key>
Returns an iterable of keys in the map

Returns IterableIterator<Key>
Inherited from Map.keys
- Defined in node_modules/typescript/lib/lib.es2015.iterable.d.ts:129

last

last(): undefined | Value
Obtains the last value(s) in this collection.

Returns undefined | Value
A single value if no amount is provided or an array of values, starting from the start if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:80
last(amount: number): Value[]
Obtains the last value(s) in this collection.
Parameters
- amount: number
  Amount of values to obtain from the end
Returns Value[]
A single value if no amount is provided or an array of values, starting from the start if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:81

lastKey

lastKey(): undefined | Key
Obtains the last key(s) in this collection.

Returns undefined | Key
A single key if no amount is provided or an array of keys, starting from the start if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:89
lastKey(amount: number): Key[]
Obtains the last key(s) in this collection.
Parameters
- amount: number
  Amount of keys to obtain from the end
Returns Key[]
A single key if no amount is provided or an array of keys, starting from the start if amount is negative
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:90

map

map<NewValue>(
fn: (value: Value, key: Key, collection: this) => NewValue,
): NewValue[]
Maps each item to another value into an array. Identical in behavior to Array.map().
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => NewValue
  Function that produces an element of the new array, taking three arguments
Returns NewValue[]
Example
```
collection.map(user => user.tag);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:253
map<This, NewValue>(
fn: (this: This, value: Value, key: Key, collection: this) => NewValue,
thisArg: This,
): NewValue[]
Maps each item to another value into an array. Identical in behavior to Array.map().
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => NewValue
  Function that produces an element of the new array, taking three arguments
- thisArg: This
  Value to use as this when executing the function
Returns NewValue[]
Example
```
collection.map(user => user.tag);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:254

mapValues

mapValues<NewValue>(
fn: (value: Value, key: Key, collection: this) => NewValue,
): Collection<Key, NewValue>
Maps each item to another value into a collection. Identical in behavior to Array.map().
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => NewValue
  Function that produces an element of the new collection, taking three arguments
Returns Collection<Key, NewValue>
Example
```
collection.mapValues(user => user.tag);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:266
mapValues<This, NewValue>(
fn: (this: This, value: Value, key: Key, collection: this) => NewValue,
thisArg: This,
): Collection<Key, NewValue>
Maps each item to another value into a collection. Identical in behavior to Array.map().
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => NewValue
  Function that produces an element of the new collection, taking three arguments
- thisArg: This
  Value to use as this when executing the function
Returns Collection<Key, NewValue>
Example
```
collection.mapValues(user => user.tag);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:267

merge

merge<OtherValue, ResultValue>(
    other: ReadonlyCollection<Key, OtherValue>,
    whenInSelf: (value: Value, key: Key) => Keep<ResultValue>,
    whenInOther: (valueOther: OtherValue, key: Key) => Keep<ResultValue>,
    whenInBoth: (
        value: Value,
        valueOther: OtherValue,
        key: Key,
    ) => Keep<ResultValue>,
): Collection<Key, ResultValue>
Merges two Collections together into a new Collection.
Type Parameters
- OtherValue
- ResultValue
Parameters
- other: ReadonlyCollection<Key, OtherValue>
  The other Collection to merge with
- whenInSelf: (value: Value, key: Key) => Keep<ResultValue>
  Function getting the result if the entry only exists in this Collection
- whenInOther: (valueOther: OtherValue, key: Key) => Keep<ResultValue>
  Function getting the result if the entry only exists in the other Collection
- whenInBoth: (value: Value, valueOther: OtherValue, key: Key) => Keep<ResultValue>
  Function getting the result if the entry exists in both Collections
Returns Collection<Key, ResultValue>
Example
```
// Sums up the entries in two collections.
coll.merge(
 other,
 x => ({ keep: true, value: x }),
 y => ({ keep: true, value: y }),
 (x, y) => ({ keep: true, value: x + y }),
);
```
Example
```
// Intersects two collections in a left-biased manner.
coll.merge(
 other,
 x => ({ keep: false }),
 y => ({ keep: false }),
 (x, _) => ({ keep: true, value: x }),
);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:482

partition

partition<NewKey>(
fn: (value: Value, key: Key, collection: this) => key is NewKey,
): [Collection<NewKey, Value>, Collection<Exclude<Key, NewKey>, Value>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Type Parameters
- NewKey
Parameters
- fn: (value: Value, key: Key, collection: this) => key is NewKey
  Function used to test (should return a boolean)
Returns [Collection<NewKey, Value>, Collection<Exclude<Key, NewKey>, Value>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:223
partition<NewValue>(
fn: (value: Value, key: Key, collection: this) => value is NewValue,
): [Collection<Key, NewValue>, Collection<Key, Exclude<Value, NewValue>>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Type Parameters
- NewValue
Parameters
- fn: (value: Value, key: Key, collection: this) => value is NewValue
  Function used to test (should return a boolean)
Returns [Collection<Key, NewValue>, Collection<Key, Exclude<Value, NewValue>>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:224
partition(
fn: (value: Value, key: Key, collection: this) => unknown,
): [Collection<Key, Value>, Collection<Key, Value>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
Returns [Collection<Key, Value>, Collection<Key, Value>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:225
partition<This, NewKey>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => key is NewKey,
    thisArg: This,
): [Collection<NewKey, Value>, Collection<Exclude<Key, NewKey>, Value>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Type Parameters
- This
- NewKey
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => key is NewKey
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns [Collection<NewKey, Value>, Collection<Exclude<Key, NewKey>, Value>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:226
partition<This, NewValue>(
    fn: (
        this: This,
        value: Value,
        key: Key,
        collection: this,
    ) => value is NewValue,
    thisArg: This,
): [Collection<Key, NewValue>, Collection<Key, Exclude<Value, NewValue>>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Type Parameters
- This
- NewValue
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => value is NewValue
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns [Collection<Key, NewValue>, Collection<Key, Exclude<Value, NewValue>>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:227
partition<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): [Collection<Key, Value>, Collection<Key, Value>]
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns [Collection<Key, Value>, Collection<Key, Value>]
Example
```
const [big, small] = collection.partition(guild => guild.memberCount > 250);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:228

random

random(): undefined | Value
Obtains unique random value(s) from this collection.

Returns undefined | Value
A single value if no amount is provided or an array of values
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:113
random(amount: number): Value[]
Obtains unique random value(s) from this collection.
Parameters
- amount: number
  Amount of values to obtain randomly
Returns Value[]
A single value if no amount is provided or an array of values
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:114

randomKey

randomKey(): undefined | Key
Obtains unique random key(s) from this collection.

Returns undefined | Key
A single key if no amount is provided or an array
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:121
randomKey(amount: number): Key[]
Obtains unique random key(s) from this collection.
Parameters
- amount: number
  Amount of keys to obtain randomly
Returns Key[]
A single key if no amount is provided or an array
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:122

reduce

reduce(
    fn: (
        accumulator: Value,
        value: Value,
        key: Key,
        collection: this,
    ) => Value,
    initialValue?: Value,
): Value
Applies a function to produce a single value. Identical in behavior to Array.reduce().
Parameters
- fn: (accumulator: Value, value: Value, key: Key, collection: this) => Value
  Function used to reduce, taking four arguments; accumulator, currentValue, currentKey, and collection
- OptionalinitialValue: Value
  Starting value for the accumulator
Returns Value
Example
```
collection.reduce((acc, guild) => acc + guild.memberCount, 0);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:310
reduce<InitialValue>(
    fn: (
        accumulator: InitialValue,
        value: Value,
        key: Key,
        collection: this,
    ) => InitialValue,
    initialValue: InitialValue,
): InitialValue
Applies a function to produce a single value. Identical in behavior to Array.reduce().
Type Parameters
- InitialValue
Parameters
- fn: (
      accumulator: InitialValue,
      value: Value,
      key: Key,
      collection: this,
  ) => InitialValue
  Function used to reduce, taking four arguments; accumulator, currentValue, currentKey, and collection
- initialValue: InitialValue
  Starting value for the accumulator
Returns InitialValue
Example
```
collection.reduce((acc, guild) => acc + guild.memberCount, 0);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:311

reduceRight

reduceRight(
    fn: (
        accumulator: Value,
        value: Value,
        key: Key,
        collection: this,
    ) => Value,
    initialValue?: Value,
): Value
Applies a function to produce a single value. Identical in behavior to Array.reduceRight().
Parameters
- fn: (accumulator: Value, value: Value, key: Key, collection: this) => Value
  Function used to reduce, taking four arguments; accumulator, value, key, and collection
- OptionalinitialValue: Value
  Starting value for the accumulator
Returns Value
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:319
reduceRight<InitialValue>(
    fn: (
        accumulator: InitialValue,
        value: Value,
        key: Key,
        collection: this,
    ) => InitialValue,
    initialValue: InitialValue,
): InitialValue
Applies a function to produce a single value. Identical in behavior to Array.reduceRight().
Type Parameters
- InitialValue
Parameters
- fn: (
      accumulator: InitialValue,
      value: Value,
      key: Key,
      collection: this,
  ) => InitialValue
  Function used to reduce, taking four arguments; accumulator, value, key, and collection
- initialValue: InitialValue
  Starting value for the accumulator
Returns InitialValue
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:320

reverse

reverse(): this
Identical to Array.reverse() but returns a Collection instead of an Array.

Returns this
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:127

set

set(key: Key, value: Value): this
Adds a new element with a specified key and value to the Map. If an element with the same key already exists, the element will be updated.
Parameters
- key: Key
- value: Value
Returns this
Inherited from Map.set
- Defined in node_modules/typescript/lib/lib.es2015.collection.d.ts:41

some

some(fn: (value: Value, key: Key, collection: this) => unknown): boolean
Checks if there exists an item that passes a test. Identical in behavior to Array.some().
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
Returns boolean
Example
```
collection.some(user => user.discriminator === '0000');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:279
some<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): boolean
Checks if there exists an item that passes a test. Identical in behavior to Array.some().
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns boolean
Example
```
collection.some(user => user.discriminator === '0000');
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:280

sort

sort(compareFunction?: Comparator<Key, Value>): this
The sort method sorts the items of a collection in place and returns it. The sort is not necessarily stable in Node 10 or older. The default sort order is according to string Unicode code points.
Parameters
- OptionalcompareFunction: Comparator<Key, Value>
  Specifies a function that defines the sort order. If omitted, the collection is sorted according to each character's Unicode code point value, according to the string conversion of each element.
Returns this
Example
```
collection.sort((userA, userB) => userA.createdTimestamp - userB.createdTimestamp);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:393

sweep

sweep(fn: (value: Value, key: Key, collection: this) => unknown): number
Removes items that satisfy the provided filter function.
Parameters
- fn: (value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
Returns number
The number of removed entries
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:192
sweep<This>(
fn: (this: This, value: Value, key: Key, collection: this) => unknown,
thisArg: This,
): number
Removes items that satisfy the provided filter function.
Type Parameters
- This
Parameters
- fn: (this: This, value: Value, key: Key, collection: this) => unknown
  Function used to test (should return a boolean)
- thisArg: This
  Value to use as this when executing the function
Returns number
The number of removed entries
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:193

symmetricDifference

symmetricDifference<OtherValue>(
other: ReadonlyCollection<Key, OtherValue>,
): Collection<Key, Value | OtherValue>
Returns a new collection containing only the items where the keys are present in either collection, but not both.
Type Parameters
- OtherValue
Parameters
- other: ReadonlyCollection<Key, OtherValue>
  The other Collection to filter against
Returns Collection<Key, Value | OtherValue>
Example
```
const col1 = new Collection([['a', 1], ['b', 2]]);
const col2 = new Collection([['a', 1], ['c', 3]]);
const symmetricDifference = col1.symmetricDifference(col2);
console.log(col1.symmetricDifference(col2));
// => Collection { 'b' => 2, 'c' => 3 }
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:453

tap

tap(fn: (collection: this) => void): this
Runs a function on the collection and returns the collection.
Parameters
- fn: (collection: this) => void
  Function to execute
Returns this
Example
```
collection
 .tap(coll => console.log(coll.size))
 .filter(user => user.bot)
 .tap(coll => console.log(coll.size))
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:351
tap<This>(fn: (this: This, collection: this) => void, thisArg: This): this
Runs a function on the collection and returns the collection.
Type Parameters
- This
Parameters
- fn: (this: This, collection: this) => void
  Function to execute
- thisArg: This
  Value to use as this when executing the function
Returns this
Example
```
collection
 .tap(coll => console.log(coll.size))
 .filter(user => user.bot)
 .tap(coll => console.log(coll.size))
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:352

toJSON

toJSON(): [Key, Value][]
Returns [Key, Value][]
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:502

toReversed

toReversed(): Collection<Key, Value>
Identical to Array.toReversed() but returns a Collection instead of an Array.

Returns Collection<Key, Value>
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:487

toSorted

toSorted(compareFunction?: Comparator<Key, Value>): Collection<Key, Value>
The sorted method sorts the items of a collection and returns it. The sort is not necessarily stable in Node 10 or older. The default sort order is according to string Unicode code points.
Parameters
- OptionalcompareFunction: Comparator<Key, Value>
  Specifies a function that defines the sort order. If omitted, the collection is sorted according to each character's Unicode code point value, according to the string conversion of each element.
Returns Collection<Key, Value>
Example
```
collection.sorted((userA, userB) => userA.createdTimestamp - userB.createdTimestamp);
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:501

union

union<OtherValue>(
other: ReadonlyCollection<Key, OtherValue>,
): Collection<Key, Value | OtherValue>
Returns a new collection containing the items where the key is present in either of the collections.
Type Parameters
- OtherValue
Parameters
- other: ReadonlyCollection<Key, OtherValue>
  The other Collection to filter against
Returns Collection<Key, Value | OtherValue>
Remarks
If the collections have any items with the same key, the value from the first collection will be used.
Example
```
const col1 = new Collection([['a', 1], ['b', 2]]);
const col2 = new Collection([['a', 1], ['b', 3], ['c', 3]]);
const union = col1.union(col2);
console.log(union);
// => Collection { 'a' => 1, 'b' => 2, 'c' => 3 }
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:424

values

values(): IterableIterator<Value>
Returns an iterable of values in the map

Returns IterableIterator<Value>
Inherited from Map.values
- Defined in node_modules/typescript/lib/lib.es2015.iterable.d.ts:134

`Static`combineEntries

combineEntries<Key, Value>(
entries: Iterable<[Key, Value]>,
combine: (firstValue: Value, secondValue: Value, key: Key) => Value,
): Collection<Key, Value>
Creates a Collection from a list of entries.
Type Parameters
- Key
- Value
Parameters
- entries: Iterable<[Key, Value]>
  The list of entries
- combine: (firstValue: Value, secondValue: Value, key: Key) => Value
  Function to combine an existing entry with a new one
Returns Collection<Key, Value>
Example
```
Collection.combineEntries([["a", 1], ["b", 2], ["a", 2]], (x, y) => x + y);
// returns Collection { "a" => 3, "b" => 2 }
```
- Defined in node_modules/@discordjs/rest/node_modules/@discordjs/collection/dist/index.d.ts:515

`Static`groupBy

groupBy<K, T>(
items: Iterable<T>,
keySelector: (item: T, index: number) => K,
): Map<K, T[]>
Groups members of an iterable according to the return value of the passed callback.
Type Parameters
- K
- T
Parameters
- items: Iterable<T>
  An iterable.
- keySelector: (item: T, index: number) => K
  A callback which will be invoked for each item in items.
Returns Map<K, T[]>
- Defined in node_modules/typescript/lib/lib.esnext.collection.d.ts:25

Class Collection<Key, Value>

Type Parameters

Hierarchy

Index

Constructors

Properties

Methods

Constructors

constructor

Type Parameters

Parameters

Returns Collection<Key, Value>

Type Parameters

Parameters

Returns Collection<Key, Value>

Properties

Readonly[toStringTag]

constructor

Readonlysize

Returns

Static Readonly[species]

Methods

[iterator]

Returns IterableIterator<[Key, Value]>

at

Parameters

Returns undefined | Value

clear

Returns void

clone

Returns Collection<Key, Value>

Example

concat

Parameters

Returns Collection<Key, Value>

Example

delete

Parameters

Returns boolean

difference

Parameters

Returns Collection<Key, Value>

Example

each

Parameters

Returns this

Example

Type Parameters

Parameters

Returns this

Example

ensure

Parameters

Returns Value

Example

entries

Returns IterableIterator<[Key, Value]>

equals

Parameters

Returns boolean

every

Type Parameters

Parameters

Returns this is Collection<NewKey, Value>

Example

Type Parameters

Parameters

Returns this is Collection<Key, NewValue>

Example

Parameters

Returns boolean

Example

Type Parameters

Parameters

Returns this is Collection<NewKey, Value>

Example

Type Parameters

Parameters

Returns this is Collection<Key, NewValue>

Example

`Readonly`[toStringTag]

`Readonly`size

`Static` `Readonly`[species]