If this collection is empty.
Optional
extraOptions: ExtraOptions<M, C, E>See: Array#every
Optional
thisArg: ThisArgOptional
thisArg: ThisArgSee: Array#filter
Optional
thisArg: ThisArgOptional
thisArg: ThisArgSee: Array#find
Optional
thisArg: ThisArgOptional
thisArg: ThisArgSee: Array#findIndex
Optional
thisArg: unknownExecutes a provided function once per each key/value pair in the Map, in insertion order.
Optional
thisArg: anyReturns 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.
Returns the element associated with the specified key. If no element is associated with the specified key, undefined is returned.
See: Array#map
Optional
thisArg: unknownSee: Array#reduce
See: Array#reduceRight
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.
See: Array#some
Optional
thisArg: ThisArgReadonly
[toReadonly
sizethe number of elements in the Map.
Static
Readonly
[species]
This is an internal class, you should not use it in your projects. If you want a collection type for your own projects, look at Collection.