declare class Collection<K, V> extends Map<K, V>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
K
V
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.
external clone() : Collection<K, V>
Creates an identical shallow copy of this collection.
const newColl = someColl.clone();staticexternal combineEntries<K
V
>() : Collection<K, V>
K
V
Creates a Collection from a list of entries.
Collection.combineEntries([["a", 1], ["b", 2], ["a", 2]], (x, y) => x + y);
// returns Collection { "a" => 3, "b" => 2 }external concat(...collections: ReadonlyCollection<K, V>[]) : Collection<K, V>
Combines this collection with others into a new collection. None of the source collections are modified.
const newColl = someColl.concat(someOtherColl, anotherColl, ohBoyAColl);external difference<T
>(other: ReadonlyCollection<K, T>) : Collection<K, T | V>
T
The difference method returns a new structure containing items where the key is present in one of the original structures but not the other.
Identical to Map.forEach(), but returns the collection instead of undefined.
collection
.each(user => console.log(user.username))
.filter(user => user.bot)
.each(user => console.log(user.username));Obtains the value of the given key if it exists, otherwise sets and returns the value provided by the default value generator.
collection.ensure(guildId, () => defaultGuildConfig);external equals(collection: ReadonlyCollection<K, V>) : 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.
Returns: Whether the collections have identical contents
external every<K2 extends K
>() : this is Collection<K2, V>
K2 extends K
Checks if all items passes a test. Identical in behavior to Array.every().
collection.every(user => !user.bot);external filter<K2 extends K
>() : Collection<K2, V>
K2 extends K
Identical to Array.filter(), but returns a Collection instead of an Array.
collection.filter(user => user.username === 'Bob');external find<V2 extends V
>() : V2 | undefined
V2 extends V
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.
collection.find(user => user.username === 'Bob');external findKey<K2 extends K
>() : K2 | undefined
K2 extends K
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.
collection.findKey(user => user.username === 'Bob');external flatMap<T
>(fn: (value: V, key: K, collection: this) => Collection<K, T>) : Collection<K, T>
T
Maps each item into a Collection, then joins the results into a single Collection. Identical in behavior to Array.flatMap().
collection.flatMap(guild => guild.members.cache);Checks if all of the elements exist in the collection.
Returns: true if all of the elements exist, false if at least one does not exist.
Checks if any of the elements exist in the collection.
Returns: true if any of the elements exist, false if none exist.
external intersect<T
>(other: ReadonlyCollection<K, T>) : Collection<K, T>
T
The intersect method returns a new structure containing items where the keys and values are present in both original structures.
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.
Maps each item to another value into an array. Identical in behavior to Array.map().
collection.map(user => user.tag);external mapValues<T
>() : Collection<K, T>
T
Maps each item to another value into a collection. Identical in behavior to Array.map().
collection.mapValues(user => user.tag);external merge<T
R
>(other: ReadonlyCollection<K, T>) : Collection<K, R>
T
R
Merges two Collections together into a new Collection.
// 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 }),
);// Intersects two collections in a left-biased manner.
coll.merge(
other,
x => ({ keep: false }),
y => ({ keep: false }),
(x, _) => ({ keep: true, value: x }),
);external partition<K2 extends K
>() : [Collection<K2, V>, Collection<Exclude<K, K2>, V>]
K2 extends K
Partitions the collection into two collections where the first collection contains the items that passed and the second contains the items that failed.
const [big, small] = collection.partition(guild => guild.memberCount > 250);Applies a function to produce a single value. Identical in behavior to Array.reduce().
collection.reduce((acc, guild) => acc + guild.memberCount, 0);Identical to Array.reverse() but returns a Collection instead of an Array.
Checks if there exists an item that passes a test. Identical in behavior to Array.some().
collection.some(user => user.discriminator === '0000');external sort(compareFunction?: Comparator<K, V>) : 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.
collection.sort((userA, userB) => userA.createdTimestamp - userB.createdTimestamp);external sorted(compareFunction?: Comparator<K, V>) : Collection<K, V>
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.
collection.sorted((userA, userB) => userA.createdTimestamp - userB.createdTimestamp);external subtract<T
>(other: ReadonlyCollection<K, T>) : Collection<K, V>
T
The subtract method returns a new structure containing items where the keys and values of the original structure are not present in the other.
external tap(fn: (collection: this) => void) : this
Runs a function on the collection and returns the collection.
collection
.tap(coll => console.log(coll.size))
.filter(user => user.bot)
.tap(coll => console.log(coll.size))