JavaScript Symbol.keyFor() function

JavascriptWeb DevelopmentObject Oriented Programming

The JavaScript Symbol.iskeyFor() is used for finding the key that is associated with a given symbol. The key is retrieved from the global symbol registry.

Following is the code for Symbol.keyFor() function −


 Live Demo

<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   div {
      font-size: 20px;
      font-weight: 500;
<h1>JavaScript Symbol.keyFor() function</h1>
<div class="sample"></div>
<button class="Btn">CLICK HERE</button>
Click on the above button to find the keys for the symbol
   let fillEle = document.querySelector(".sample");
   const symbol = Symbol.for("HELLO");
   const symbol1 = Symbol.for("NEW");
   const symbol2 = Symbol.for(711);
   document.querySelector(".Btn").addEventListener("click", () => {
      fillEle.innerHTML += "symbol = " + Symbol.keyFor(symbol) + "<br>";
      fillEle.innerHTML += "symbol1 = " + Symbol.keyFor(symbol1) + "<br>";
      fillEle.innerHTML += "symbol2 = " + Symbol.keyFor(symbol2) + "<br>";


On clicking the “CLICK HERE” button −

Updated on 08-May-2020 11:57:09