Map.prototype.set() - JavaScript 编辑

The set() method adds or updates an element with a specified key and a value to a Map object.

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The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

myMap.set(key, value)

Parameters

key

The key of the element to add to the Map object.

value

The value of the element to add to the Map object.

Return value

The Map object.

Examples

Using set()

let myMap = new Map()

// Add new elements to the map
myMap.set('bar', 'foo')
myMap.set(1, 'foobar')

// Update an element in the map
myMap.set('bar', 'baz')

Using the set() with chaining

Since the set() method returns back the same Map object, you can chain the method call like below:

// Add new elements to the map with chaining.
myMap.set('bar', 'foo')
     .set(1, 'foobar')
     .set(2, 'baz');

Specifications

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

Browser compatibility

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See also

• Map
• Map.prototype.get()
• Map.prototype.has()