JavaScript Symbol.for() Method

The JavaScript Symbol.for() method is used to search for existing symbol in a runtime-wide symbol registry with the provided key and returns if it found. Otherwise, a new symbol gets created with this key.

Syntax

Parameters

Key: The Keys to the symbol.

Return value

Existing symbol with the given key if found otherwise, a new symbol is created and returned.

Browser Support

Chrome	40
Safari	9
Firefox	36
Opera	Yes

Example 1

<script>
//JavaScript to illustrate Symbol.for
// read from the registry
// if the symbol did not exist, it is created
var i = Symbol.for("i");
var o = Symbol.for("i");
 document.write(i==o); 
//expected output: true	
</script>

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Output:

true

Example 2

<script>
//JavaScript to illustrate Symbol.key
// read from the registry
var JavaTpoint = Symbol.for('hello'); // If the Symbol does not exist, it's created
var Java = Symbol.for('hello'); // The Symbol exists, so it is returned
document.write(JavaTpoint === Java); // true
//expected output: true
</script>

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Output: