JavaScript Symbol keyFor() Method

by Online Tutorials Library July 22, 2022

JavaScript Symbol.keyFor() Method

The JavaScript Symbol.keyFor() method uses the global symbol registry to look up the key for the symbol. So it doesn’t work for non-global symbols. If the symbol is not global, it won’t be able to find it and return undefined.

Syntax

Parameters

Symbol(required): The symbol to find a key.

Return value

A string representing the key for the given symbol if one is found on the global registry

Browser Support

Chrome	40
Safari	9
Firefox	36
Opera	Yes

Example 1

  <script>  //JavaScript to illustrate Symbol.keyFor  var i = Symbol.for(“TutorAspire”);  var j = Symbol.for(“Java”);  document.write(Symbol.keyFor(i));  document.write(“<br>”);  document.write(Symbol.keyFor(j));   //expected output: TutorAspire //Java  </script>  

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Output:

TutorAspire  Java

Example 2

  <script>  //JavaScript to illustrate Symbol.keyFor  var TutorAspire = Symbol.for(‘Done’);  var Java   = Symbol.for(‘Done’);  document.write(TutorAspire === Java);  document.write(“<br>”);  document.write(Symbol.keyFor(TutorAspire));  //expected output: true  //Done  </script>  

Test it Now

Output:

true  Done

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