WeakMap.prototype.set()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The set()
method of WeakMap
instances adds a new element with a specified key
and value to this WeakMap
.
Try it
Syntax
js
set(key, value)
Parameters
key
-
Must be either an object or a non-registered symbol. The key of the entry to add to the
WeakMap
object. value
-
Any value representing the value of the entry to add to the
WeakMap
object.
Return value
The WeakMap
object.
Exceptions
TypeError
-
Thrown if
key
is not an object or a non-registered symbol.
Examples
Using the set() method
js
const wm = new WeakMap();
const obj = {};
// Add new elements to the WeakMap
wm.set(obj, "foo").set(window, "bar"); // chainable
// Update an element in the WeakMap
wm.set(obj, "baz");
// Using a non-registered symbol as key
const sym = Symbol("foo");
wm.set(sym, "baz");
wm.set(Symbol.iterator, "qux");
Specifications
Specification |
---|
ECMAScript Language Specification # sec-weakmap.prototype.set |
Browser compatibility
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