JavaScript regex program to display name to be only numbers, letters and underscore.

Javascript Web Development Object Oriented Programming

Following is the code to to display name to be only numbers, letters and underscore using regex in JavaScript −

Example

<!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>, letters and underscore only regex match</h1>
<div style="color: green;" class="result"></div>
<input type="text" class="txt" /&lgt;
<button class="Btn"&g;CHECK</button>
<h3>
Click the above button to check if the text contains only numbers, letters
and underscore or not
</h3>
<script>
   let resEle = document.querySelector(".result");
   document.querySelector(".Btn").addEventListener("click", () => {
      var str = document.querySelector(".txt").value;
      var regex = /^\w+$/;
      var match = str.match(regex);
      if (match) resEle.innerHTML = "The text entered is valid";
      else resEle.innerHTML = "The text enterd is not valid";
   });
</script>
</body>
</html>