How can we validate decimal numbers in JavaScript?

JavascriptWeb DevelopmentObject Oriented Programming

Following is the code to validate decimal numbers in JavaScript −

Example

 Live Demo

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .result {
      font-size: 20px;
      font-weight: 500;
   }
</style>
</head>
<body>
<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>
<script>
   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";
   });
</script>
</body>
</html>

Output

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’ −

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