isIpv4 method Null safety

bool? isIpv4()

Checks whether the String is valid IPv4.

Example 1

String foo = '192.168.1.14';
bool isIpv4 = foo.isIpv4(); // returns true

Example 2

String foo = '192.168.1.14.150.1225';
bool isIpv4 = foo.isIpv4(); // returns false

Implementation

bool? isIpv4() {
  if (this == null) {
    return null;
  }
  if (this!.isEmpty) {
    return false;
  }
  var regex = RegExp(
      r'((?:^|\s)([a-z]{3,6}(?=://))?(://)?((?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.(?:25[0-5]|2[0-4]\d|[01]?\d\d?))(?::(\d{2,5}))?(?:\s|$))');
  return regex.hasMatch(this!);
}