Check MAC-address
MAC-address of a network interface consists of 6 two-digit hex numbers separated by a colon.
For instance: '01:32:54:67:89:AB'.
Write a regexp that checks whether a string is MAC-address.
Usage:
let regexp = /your regexp/;
alert( regexp.test('01:32:54:67:89:AB') ); // true
alert( regexp.test('0132546789AB') ); // false (no colons)
alert( regexp.test('01:32:54:67:89') ); // false (5 numbers, must be 6)
alert( regexp.test('01:32:54:67:89:ZZ') ) // false (ZZ at the end)A two-digit hex number is [0-9a-f]{2} (assuming the flag i is set).
We need that number NN, and then :NN repeated 5 times (more numbers);
The regexp is: [0-9a-f]{2}(:[0-9a-f]{2}){5}
Now let’s show that the match should capture all the text: start at the beginning and end at the end. That’s done by wrapping the pattern in ^...$.
Finally:
let regexp = /^[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}$/i;
alert( regexp.test('01:32:54:67:89:AB') ); // true
alert( regexp.test('0132546789AB') ); // false (no colons)
alert( regexp.test('01:32:54:67:89') ); // false (5 numbers, need 6)
alert( regexp.test('01:32:54:67:89:ZZ') ) // false (ZZ in the end)