How can we validate decimal numbers in JavaScript?

JavascriptWeb DevelopmentObject Oriented Programming

Following is the code to validate decimal numbers in JavaScript −


 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;
   .result {
      font-size: 20px;
      font-weight: 500;
<h1>Validate decimal numbers in JavaScript</h1>
<div style="color: green;" class="result"></div>
<input type="number" class="num" />
<button class="Btn">CHECK</button>
<h3>Click the above button to check if a valid decimal number is entered or not</h3>
   let resEle = document.querySelector(".result");
   document.querySelector(".Btn").addEventListener("click", () => {
      var str = document.querySelector(".num").value;
      var regex = /^[-+]?[0-9]+\.[0-9]+$/;
      var match = str.match(regex);
      if (match) resEle.innerHTML = "The number given is a decimal number";
      else resEle.innerHTML = "The number given is not a decimal number";


The above code will produce the following output −

On entering a normal number and clicking on ‘CHECK’ button −

On entering a decimal number and clicking on ‘CHECK’ −

Published on 17-Jul-2020 12:31:06