Class: Collection<K, V>
Extends
Collection<K,V>
Type Parameters
• K
• V
Constructors
new Collection()
new Collection<
K,V>(entries?):Collection<K,V>
Parameters
• entries?: readonly readonly [K, V][]
Returns
Collection<K, V>
Inherited from
BaseCollection<K, V>.constructor
new Collection()
new Collection<
K,V>(iterable?):Collection<K,V>
Parameters
• iterable?: Iterable<readonly [K, V]>
Returns
Collection<K, V>
Inherited from
BaseCollection<K, V>.constructor
Properties
[toStringTag]
readonly[toStringTag]:string
Inherited from
BaseCollection.[toStringTag]
constructor
constructor:
CollectionConstructor
The initial value of Object.prototype.constructor is the standard built-in Object constructor.
Inherited from
BaseCollection.constructor
size
readonlysize:number
Inherited from
BaseCollection.size
[species]
readonlystatic[species]:MapConstructor
Inherited from
BaseCollection.[species]
Methods
[iterator]()
[iterator]():
IterableIterator<[K,V]>
Returns an iterable of entries in the map.
Returns
IterableIterator<[K, V]>
Inherited from
BaseCollection.[iterator]
at()
at(
index):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.
Parameters
• index: number
The index of the element to obtain
Returns
V
Inherited from
BaseCollection.at
clear()
clear():
void
Returns
void
Inherited from
BaseCollection.clear
clone()
clone():
Collection<K,V>
Creates an identical shallow copy of this collection.
Returns
Collection<K, V>
Example
const newColl = someColl.clone();
Inherited from
BaseCollection.clone
concat()
concat(...
collections):Collection<K,V>
Combines this collection with others into a new collection. None of the source collections are modified.
Parameters
• ...collections: ReadonlyCollection<K, V>[]
Collections to merge
Returns
Collection<K, V>
Example
const newColl = someColl.concat(someOtherColl, anotherColl, ohBoyAColl);
Inherited from
BaseCollection.concat
delete()
delete(
key):boolean
Parameters
• key: K
Returns
boolean
true if an element in the Map existed and has been removed, or false if the element does not exist.
Inherited from
BaseCollection.delete
difference()
difference<
T>(other):Collection<K,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.
Type Parameters
• T
Parameters
• other: ReadonlyCollection<K, T>
The other Collection to filter against
Returns
Collection<K, V | T>
Inherited from
BaseCollection.difference
each()
each(fn)
each(
fn):this
Identical to Map.forEach(), but returns the collection instead of undefined.
Parameters
• fn
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));
Inherited from
BaseCollection.each
each(fn, thisArg)
each<
T>(fn,thisArg):this
Type Parameters
• T
Parameters
• fn
• thisArg: T
Returns
this
Inherited from
BaseCollection.each
ensure()
ensure(
key,defaultValueGenerator):V
Obtains the value of the given key if it exists, otherwise sets and returns the value provided by the default value generator.
Parameters
• key: K
The key to get if it exists, or set otherwise
• defaultValueGenerator
A function that generates the default value
Returns
V
Example
collection.ensure(guildId, () => defaultGuildConfig);
Inherited from
BaseCollection.ensure
entries()
entries():
IterableIterator<[K,V]>
Returns an iterable of key, value pairs for every entry in the map.
Returns
IterableIterator<[K, V]>
Inherited from
BaseCollection.entries
equals()
equals(
collection):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<K, V>
Collection to compare with
Returns
boolean
Whether the collections have identical contents
Inherited from
BaseCollection.equals
every()
every(fn)
every<
K2>(fn):this is Collection<K2, V>
Checks if all items passes a test. Identical in behavior to Array.every().
Type Parameters
• K2
Parameters
• fn
Function used to test (should return a boolean)
Returns
this is Collection<K2, V>
Example
collection.every(user => !user.bot);
Inherited from
BaseCollection.every
every(fn)
every<
V2>(fn):this is Collection<K, V2>
Type Parameters
• V2
Parameters
• fn
Returns
this is Collection<K, V2>
Inherited from
BaseCollection.every
every(fn)
every(
fn):boolean
Parameters
• fn
Returns
boolean
Inherited from
BaseCollection.every
every(fn, thisArg)
every<
This,K2>(fn,thisArg):this is Collection<K2, V>
Type Parameters
• This
• K2
Parameters
• fn
• thisArg: This
Returns
this is Collection<K2, V>
Inherited from
BaseCollection.every
every(fn, thisArg)
every<
This,V2>(fn,thisArg):this is Collection<K, V2>
Type Parameters
• This
• V2
Parameters
• fn
• thisArg: This
Returns
this is Collection<K, V2>
Inherited from
BaseCollection.every
every(fn, thisArg)
every<
This>(fn,thisArg):boolean
Type Parameters
• This
Parameters
• fn
• thisArg: This
Returns
boolean
Inherited from
BaseCollection.every
filter()
filter(fn)
filter<
K2>(fn):Collection<K2,V>
Identical to Array.filter(), but returns a Collection instead of an Array.
Type Parameters
• K2
Parameters
• fn
The function to test with (should return boolean)
Returns
Collection<K2, V>
Example
collection.filter(user => user.username === 'Bob');
Inherited from
BaseCollection.filter
filter(fn)
filter<
V2>(fn):Collection<K,V2>
Type Parameters
• V2
Parameters
• fn
Returns
Collection<K, V2>
Inherited from
BaseCollection.filter
filter(fn)
filter(
fn):Collection<K,V>
Parameters
• fn
Returns
Collection<K, V>
Inherited from
BaseCollection.filter
filter(fn, thisArg)
filter<
This,K2>(fn,thisArg):Collection<K2,V>
Type Parameters
• This
• K2
Parameters
• fn
• thisArg: This
Returns
Collection<K2, V>
Inherited from
BaseCollection.filter
filter(fn, thisArg)
filter<
This,V2>(fn,thisArg):Collection<K,V2>
Type Parameters
• This
• V2
Parameters
• fn
• thisArg: This
Returns
Collection<K, V2>
Inherited from
BaseCollection.filter
filter(fn, thisArg)
filter<
This>(fn,thisArg):Collection<K,V>
Type Parameters
• This
Parameters
• fn
• thisArg: This
Returns
Collection<K, V>
Inherited from
BaseCollection.filter
find()
find(fn)
find<
V2>(fn):V2
Searches for a single item where the given function returns a truthy value. This behaves like
Array.find().
id property, and if you want to find by id you
should use the get method. See
MDN for details.
Type Parameters
• V2
Parameters
• fn
The function to test with (should return boolean)
Returns
V2
Example
collection.find(user => user.username === 'Bob');
Inherited from
BaseCollection.find
find(fn)
find(
fn):V
Parameters
• fn
Returns
V
Inherited from
BaseCollection.find
find(fn, thisArg)
find<
This,V2>(fn,thisArg):V2
Type Parameters
• This
• V2
Parameters
• fn
• thisArg: This
Returns
V2
Inherited from
BaseCollection.find
find(fn, thisArg)
find<
This>(fn,thisArg):V
Type Parameters
• This
Parameters
• fn
• thisArg: This
Returns
V
Inherited from
BaseCollection.find
findKey()
findKey(fn)
findKey<
K2>(fn):K2
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
• K2
Parameters
• fn
The function to test with (should return boolean)
Returns
K2
Example
collection.findKey(user => user.username === 'Bob');
Inherited from
BaseCollection.findKey
findKey(fn)
findKey(
fn):K
Parameters
• fn
Returns
K
Inherited from
BaseCollection.findKey
findKey(fn, thisArg)
findKey<
This,K2>(fn,thisArg):K2
Type Parameters
• This
• K2
Parameters
• fn
• thisArg: This
Returns
K2
Inherited from
BaseCollection.findKey
findKey(fn, thisArg)
findKey<
This>(fn,thisArg):K
Type Parameters
• This
Parameters
• fn
• thisArg: This
Returns
K
Inherited from
BaseCollection.findKey
first()
first()
first():
V
Obtains the first value(s) in this collection.
Returns
V
A single value if no amount is provided or an array of values, starting from the end if amount is negative
Inherited from
BaseCollection.first
first(amount)
first(
amount):V[]
Parameters
• amount: number
Returns
V[]
Inherited from
BaseCollection.first
firstKey()
firstKey()
firstKey():
K
Obtains the first key(s) in this collection.
Returns
K
A single key if no amount is provided or an array of keys, starting from the end if amount is negative
Inherited from
BaseCollection.firstKey
firstKey(amount)
firstKey(
amount):K[]
Parameters
• amount: number
Returns
K[]
Inherited from
BaseCollection.firstKey
flatMap()
flatMap(fn)
flatMap<
T>(fn):Collection<K,T>
Maps each item into a Collection, then joins the results into a single Collection. Identical in behavior to Array.flatMap().
Type Parameters
• T
Parameters
• fn
Function that produces a new Collection
Returns
Collection<K, T>
Example
collection.flatMap(guild => guild.members.cache);
Inherited from
BaseCollection.flatMap
flatMap(fn, thisArg)
flatMap<
T,This>(fn,thisArg):Collection<K,T>
Type Parameters
• T
• This
Parameters
• fn
• thisArg: This
Returns
Collection<K, T>
Inherited from
BaseCollection.flatMap
forEach()
forEach(
callbackfn,thisArg?):void
Executes a provided function once per each key/value pair in the Map, in insertion order.
Parameters
• callbackfn
• thisArg?: any
Returns
void
Inherited from
BaseCollection.forEach
get()
get(
key):V
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: K
Returns
V
Returns the element associated with the specified key. If no element is associated with the specified key, undefined is returned.
Inherited from
BaseCollection.get
has()
has(
key):boolean
Parameters
• key: K
Returns
boolean
boolean indicating whether an element with the specified key exists or not.
Inherited from
BaseCollection.has
hasAll()
hasAll(...
keys):boolean
Checks if all of the elements exist in the collection.
Parameters
• ...keys: K[]
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.
Inherited from
BaseCollection.hasAll
hasAny()
hasAny(...
keys):boolean
Checks if any of the elements exist in the collection.
Parameters
• ...keys: K[]
The keys of the elements to check for
Returns
boolean
true if any of the elements exist, false if none exist.
Inherited from
BaseCollection.hasAny
intersect()
intersect<
T>(other):Collection<K,T>
The intersect method returns a new structure containing items where the keys and values are present in both original structures.
Type Parameters
• T
Parameters
• other: ReadonlyCollection<K, T>
The other Collection to filter against
Returns
Collection<K, T>
Inherited from
BaseCollection.intersect
keyAt()
keyAt(
index):K
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
K
Inherited from
BaseCollection.keyAt
keys()
keys():
IterableIterator<K>
Returns an iterable of keys in the map
Returns
IterableIterator<K>
Inherited from
BaseCollection.keys
last()
last()
last():
V
Obtains the last value(s) in this collection.
Returns
V
A single value if no amount is provided or an array of values, starting from the start if amount is negative
Inherited from
BaseCollection.last
last(amount)
last(
amount):V[]
Parameters
• amount: number
Returns
V[]
Inherited from
BaseCollection.last
lastKey()
lastKey()
lastKey():
K
Obtains the last key(s) in this collection.
Returns
K
A single key if no amount is provided or an array of keys, starting from the start if amount is negative
Inherited from
BaseCollection.lastKey
lastKey(amount)
lastKey(
amount):K[]
Parameters
• amount: number
Returns
K[]
Inherited from
BaseCollection.lastKey
map()
map(fn)
map<
T>(fn):T[]
Maps each item to another value into an array. Identical in behavior to Array.map().
Type Parameters
• T
Parameters
• fn
Function that produces an element of the new array, taking three arguments
Returns
T[]
Example
collection.map(user => user.tag);
Inherited from
BaseCollection.map
map(fn, thisArg)
map<
This,T>(fn,thisArg):T[]
Type Parameters
• This
• T
Parameters
• fn
• thisArg: This
Returns
T[]
Inherited from
BaseCollection.map
mapValues()
mapValues(fn)
mapValues<
T>(fn):Collection<K,T>
Maps each item to another value into a collection. Identical in behavior to Array.map().
Type Parameters
• T
Parameters
• fn
Function that produces an element of the new collection, taking three arguments
Returns
Collection<K, T>
Example
collection.mapValues(user => user.tag);
Inherited from
BaseCollection.mapValues
mapValues(fn, thisArg)
mapValues<
This,T>(fn,thisArg):Collection<K,T>
Type Parameters
• This
• T
Parameters
• fn
• thisArg: This
Returns
Collection<K, T>
Inherited from
BaseCollection.mapValues
merge()
merge<
T,R>(other,whenInSelf,whenInOther,whenInBoth):Collection<K,R>
Merges two Collections together into a new Collection.
Type Parameters
• T
• R
Parameters
• other: ReadonlyCollection<K, T>
The other Collection to merge with
• whenInSelf
Function getting the result if the entry only exists in this Collection
• whenInOther
Function getting the result if the entry only exists in the other Collection
• whenInBoth
Function getting the result if the entry exists in both Collections
Returns
Collection<K, R>
Examples
// 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 }),
);
Inherited from
BaseCollection.merge
partition()
partition(fn)
partition<
K2>(fn): [Collection<K2,V>,Collection<Exclude<K,K2>,V>]
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
• K2
Parameters
• fn
Function used to test (should return a boolean)
Returns
[Collection<K2, V>, Collection<Exclude<K, K2>, V>]
Example
const [big, small] = collection.partition(guild => guild.memberCount > 250);
Inherited from
BaseCollection.partition
partition(fn)
partition<
V2>(fn): [Collection<K,V2>,Collection<K,Exclude<V,V2>>]
Type Parameters
• V2
Parameters
• fn
Returns
[Collection<K, V2>, Collection<K, Exclude<V, V2>>]
Inherited from
BaseCollection.partition
partition(fn)
partition(
fn): [Collection<K,V>,Collection<K,V>]
Parameters
• fn
Returns
[Collection<K, V>, Collection<K, V>]
Inherited from
BaseCollection.partition
partition(fn, thisArg)
partition<
This,K2>(fn,thisArg): [Collection<K2,V>,Collection<Exclude<K,K2>,V>]
Type Parameters
• This
• K2
Parameters
• fn
• thisArg: This
Returns
[Collection<K2, V>, Collection<Exclude<K, K2>, V>]
Inherited from
BaseCollection.partition
partition(fn, thisArg)
partition<
This,V2>(fn,thisArg): [Collection<K,V2>,Collection<K,Exclude<V,V2>>]
Type Parameters
• This
• V2
Parameters
• fn
• thisArg: This
Returns
[Collection<K, V2>, Collection<K, Exclude<V, V2>>]
Inherited from
BaseCollection.partition
partition(fn, thisArg)
partition<
This>(fn,thisArg): [Collection<K,V>,Collection<K,V>]
Type Parameters
• This
Parameters
• fn
• thisArg: This
Returns
[Collection<K, V>, Collection<K, V>]
Inherited from
BaseCollection.partition
random()
random()
random():
V
Obtains unique random value(s) from this collection.
Returns
V
A single value if no amount is provided or an array of values
Inherited from
BaseCollection.random
random(amount)
random(
amount):V[]
Parameters
• amount: number
Returns
V[]
Inherited from
BaseCollection.random
randomKey()
randomKey()
randomKey():
K
Obtains unique random key(s) from this collection.
Returns
K
A single key if no amount is provided or an array
Inherited from
BaseCollection.randomKey
randomKey(amount)
randomKey(
amount):K[]
Parameters
• amount: number
Returns
K[]
Inherited from
BaseCollection.randomKey
reduce()
reduce<
T>(fn,initialValue?):T
Applies a function to produce a single value. Identical in behavior to Array.reduce().
Type Parameters
• T
Parameters
• fn
Function used to reduce, taking four arguments; accumulator, currentValue, currentKey,
and collection
• initialValue?: T
Starting value for the accumulator
Returns
T
Example
collection.reduce((acc, guild) => acc + guild.memberCount, 0);
Inherited from
BaseCollection.reduce
reverse()
reverse():
this
Identical to Array.reverse() but returns a Collection instead of an Array.
Returns
this
Inherited from
BaseCollection.reverse
set()
set(
key,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: K
• value: V
Returns
this
Inherited from
BaseCollection.set
some()
some(fn)
some(
fn):boolean
Checks if there exists an item that passes a test. Identical in behavior to Array.some().
Parameters
• fn
Function used to test (should return a boolean)
Returns
boolean
Example
collection.some(user => user.discriminator === '0000');
Inherited from
BaseCollection.some
some(fn, thisArg)
some<
T>(fn,thisArg):boolean
Type Parameters
• T
Parameters
• fn
• thisArg: T
Returns
boolean
Inherited from
BaseCollection.some
sort()
sort(
compareFunction?):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
• compareFunction?: Comparator<K, V>
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);
Inherited from
BaseCollection.sort
sorted()
sorted(
compareFunction?):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.
Parameters
• compareFunction?: Comparator<K, V>
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<K, V>
Example
collection.sorted((userA, userB) => userA.createdTimestamp - userB.createdTimestamp);
Inherited from
BaseCollection.sorted
sweep()
sweep(fn)
sweep(
fn):number
Removes items that satisfy the provided filter function.
Parameters
• fn
Function used to test (should return a boolean)
Returns
number
The number of removed entries
Inherited from
BaseCollection.sweep
sweep(fn, thisArg)
sweep<
T>(fn,thisArg):number
Type Parameters
• T
Parameters
• fn
• thisArg: T
Returns
number
Inherited from
BaseCollection.sweep
tap()
tap(fn)
tap(
fn):this
Runs a function on the collection and returns the collection.
Parameters
• fn
Function to execute
Returns
this
Example
collection
.tap(coll => console.log(coll.size))
.filter(user => user.bot)
.tap(coll => console.log(coll.size))
Inherited from
BaseCollection.tap
tap(fn, thisArg)
tap<
T>(fn,thisArg):this
Type Parameters
• T
Parameters
• fn
• thisArg: T
Returns
this
Inherited from
BaseCollection.tap
toJSON()
toJSON():
any[]
Returns
any[]
Overrides
BaseCollection.toJSON
values()
values():
IterableIterator<V>
Returns an iterable of values in the map
Returns
IterableIterator<V>
Inherited from
BaseCollection.values
combineEntries()
staticcombineEntries<K,V>(entries,combine):Collection<K,V>
Creates a Collection from a list of entries.
Type Parameters
• K
• V
Parameters
• entries: Iterable<[K, V]>
The list of entries
• combine
Function to combine an existing entry with a new one
Returns
Collection<K, V>
Example
Collection.combineEntries([["a", 1], ["b", 2], ["a", 2]], (x, y) => x + y);
// returns Collection { "a" => 3, "b" => 2 }
Inherited from
BaseCollection.combineEntries