Javascript file to listen for Konami code to be entered by keyboard

konami.js

/**
 * Created by adamg on 3/29/2017.
 */
(function(){
    var charSet = ["ArrowUp","ArrowUp","ArrowDown","ArrowDown","ArrowLeft","ArrowRight","ArrowLeft","ArrowRight","b","a"];
    var charInSet = 0;
    document.addEventListener('keydown',function(e){
        if(e.key == charSet[charInSet]){
            console.log("Match for char: " + charSet[charInSet]);
            charInSet++;
            if(charInSet==charSet.length){
                console.log("secret triggered");
            }
        }
        else{
            charInSet = 0;
        }
    });
})();