JAVASCRIPT
Validate IPv4 Addresses
Implement robust IPv4 address validation in JavaScript using a regular expression to ensure proper format for network configurations or input fields.
const ipv4Regex = /^(?: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]?)$/;
function isValidIPv4(ip) {
return ipv4Regex.test(ip);
}
// Examples
console.log(isValidIPv4("192.168.1.1")); // true
console.log(isValidIPv4("10.0.0.255")); // true
console.log(isValidIPv4("255.255.255.255")); // true
console.log(isValidIPv4("0.0.0.0")); // true
console.log(isValidIPv4("192.168.1.256")); // false (invalid octet)
console.log(isValidIPv4("255.255.255")); // false (missing octet)
console.log(isValidIPv4("abc.def.ghi.jkl")); // false
How it works: This JavaScript snippet provides a regular expression to validate IPv4 addresses. It ensures that each of the four octets is a number between 0 and 255, separated by dots. This pattern is crucial for applications that require network configuration input or need to verify IP addresses entered by users, ensuring data integrity.