javascript regex to return letters only

Question

My string can be something like A01, B02, C03, possibly AA18 in the future as well. I thought I could use a regex to get just the letters and work on my regex since I haven't done much with it. I wrote this function:

function rowOffset(sequence) {
              console.log(sequence);
            var matches = /^[a-zA-Z]+$/.exec(sequence);
            console.log(matches);
            var letter = matches[0].toUpperCase();
            return letter;
}

var x = "A01";
console.log(rowOffset(x));

My matches continue to be null. Am I doing this correctly? Looking at this post, I thought the regex was correct: Regular expression for only characters a-z, A-Z

Answer 1

You can use String#replace to remove all non letters from input string:

var r = 'AA18'.replace(/[^a-zA-Z]+/g, '');
//=> "AA"