Map.prototype.size

The size accessor property returns the number of elements in a Map object.

Description

The value of size is an integer representing how many entries the Map object has. A set accessor function for size is undefined; you can not change this property.

Examples

Using size

var myMap = new Map();
myMap.set('a', 'alpha');
myMap.set('b', 'beta');
myMap.set('g', 'gamma');

myMap.size // 3

Specifications

Specification
ECMAScript (ECMA-262)
The definition of 'Map.prototype.size' in that specification.

Browser compatibility

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See also