The HTML DOM Input Text pattern property is used for setting or returning the pattern attribute of an input text field. It checks the text against a regular expression specified by the pattern property.
Syntax
Following is the syntax for −
Setting the pattern property −
textObject.pattern = regexp
Here, regexp is a regular expression against which the text field is checked.
Example
Let us look at an example for the text pattern property −
<!DOCTYPE html>
<html>
<body>
<h1>Input Text pattern property</h1>
<p>The username can either be of three numeric characters or 6 alphabet characters from a to g</p>
<form action="/Sample_page.php">
USERNAME: <input type="text" id="USR" name="user_name" pattern="[0-9]{3}|[a-g]{6}"
title="Three numeric character or 6 alphabet between a-g">
<input type="submit">
</form>
<br>
<button onclick="textPattern()">GET PATTERN</button>
<p id="Sample"></p>
<script>
function textPattern() {
var P = document.getElementById("USR").pattern;
document.getElementById("Sample").innerHTML ="The pattern attribute value is"+ P;
}
</script>
</body>
</html>Output
This will produce the following output −
On entering text in the text field that doesn’t match by the regex specified in the pattern property, the following warning would be visible −
On clicking the GET PATTERN button −
