JavaScript Program to Check IP Address Format Using Regular Expression
Write a JavaScript function to check whether a given value is valid IP value or not.
Source Code
<html>
<head>
<title>Check for valid IP address</title>
<script>
function checkIP()
{
var re = /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/
var ip = myform.ip.value
if(re.test(ip))
alert("You have entered a Valid IP address")
else
alert("You have entered an Invalid IP address")
}
</script>
</head>
<body>
<form name="myform">
Enter IP address <input type="text" id="ip"/>
<input type="button" value="Submit" onclick="checkIP()"/>
</form>
<body>
</html>
Output
