JSFiddle - React, Tailwind, and code Playground

by hicurin

JavaScript

var str = "abcda";
function checkDuplicate(str){
    for(var i = 0; i < str.length; i++){
        var c = str[i];
        if(str.replace(/[^/g, "").length >= 2){
            return true;
        }
    }
    return false;
}
alert(checkDuplicate(str));