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>Output
The above code will produce the following output −
On entering text having space between them and clicking on ‘CHECK’ −
On entering valid text and clicking on ‘CHECK’ −
