/*
* @author Nektro (Sean Denny)
* Copyright (c) 2016
*/
(function() {
    var keyStates = new Map();

    window.addEventListener('keydown', (e) => {
        keyStates.set(e.keyCode, 1);
    });
    window.addEventListener('keyup', (e) => {
        keyStates.set(e.keyCode, 0);
    });
    /**
     * Adds two numbers
     * @param {Number} a key ID
     * @return {Boolean} whether or not the specified key is currently being pressed
     */
    window.isKeyDown = function(k) {
        if (keyStates.has(k))
            if (keyStates.get(k) === 1)
                return true;
        return false;
    };
})();

@@ -292,32 +292,8 @@
 /**%0A
-     * Adds two numbers%0A
     
@@ -320,16 +320,16 @@
  key ID%0A
+
      * @
@@ -549,16 +549,16 @@
 n true;%0A
-
         
@@ -578,14 +578,373 @@
 %0A    %7D;%0A
+    /**%0A     * @param %7BArray%3CNumber%3E%7D an array of key IDs%0A     * @return %7BBoolean%7D whether or not all of the keys in the array are being pressed%0A     */%0A    window.areKeysDown = function(ka) %7B%0A        for (var y in ka)%0A            if (keyStates.has(y))%0A                if (keyStates.get(y) === 0)%0A                    return false;%0A        return true;%0A    %7D;%0A
 %7D)();%0A

Update isKeyDown.js