Get duplicate characters in string

Question

I try to match/get all repetitions in a string. This is what I\'ve done so far:

var str = \'abcabc123123\';
var REPEATED_CHARS_REGEX = /(.).*\\1/gi;

console         


        

Answer 1

This solution may be used if you don't want to use regex:

function test() {
    var stringToTest = 'find the first duplicate character in the string';
    var a = stringToTest.split('');
    for (var i=0; i