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JavaScript Map Reference


Complete Map Reference

Revised July 2025

MethodDescription
new Map() Creates a new Map object
clear() Removes all the elements from a Map
delete() Removes a Map element specified by a key
entries() Returns an iterator object with the [key, value] pairs in a Map
forEach() Invokes a callback for each key/value pair in a Map
get() Gets the value for a key in a Map
groupBy() Groups object elements according to returned callback values
has() Returns true if a key exists in a Map
keys() Returns an iterator object with the keys in a Map
set() Sets the value for a key in a Map
size Returns the number of Map elements
values() Returns an iterator object of the values in a Map

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