const regex = /^(([01]?[0-9]?[0-9]|2([0-4][0-9]|5[0-5]))\.){3}([01]?[0-9]?[0-9]|2([0-4][0-9]|5[0-5]))$/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('^(([01]?[0-9]?[0-9]|2([0-4][0-9]|5[0-5]))\\.){3}([01]?[0-9]?[0-9]|2([0-4][0-9]|5[0-5]))$', 'gm')
const str = `validates:
192.68.35.35
0.0.0.0
255.0.0.0
192.168.1.0
192.168.0.1
255.255.255.0
1.1.1.1
255.255.255.255
249.249.249.249
200.200.200.200
199.199.199.199
100.100.100.100
99.99.99.99
0.0.0.0
9.9.9.9
10.10.10.10
99.99.99.99
100.100.100.100
109.109.109.109
110.110.110.110
199.199.199.199
200.200.200.200
249.249.249.249
250.250.250.250
255.255.255.255
does not validate:
256.256.256.260
192.168.0.0/24
192.168..1
192.168.1
1
1.
1.1
1.1.
1.1.1
1.1.1.
1.1.1.1.
1.1.1.1.1
.1.1.1
01.01.01.01
09.09.09.09
1.0.0.1.0
010.1.1.1
123456
123123123123
.127.0.0.1`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions