I am trying to create a .js file for a website that upon entering the konami code Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start(enter) it will embed a video. However while entering the right keys the webpage should display something like "keep going", if a wrong key is entered it should display "wrong, try again", and allow them to start over.

I've manged to get the JavaScript working where upon entering the right code it displays an alert, and entering the wrong code displays a different code.

i've manged to get this much code using online resources but none of them explain how to get wrong, try again part

    if (window.addEventListener) {
    var keys = [],
    konami = "38,38,40,40,37,39,37,39,66,65,13";

    window.addEventListener("keydown", function(e){
    keys.push(e.keyCode);


    if (keys.toString().indexOf(konami) >= 0) 
    {            
       alert('Right');
        keys = [];
    };

    if (keys.toString().indexOf(konami) < 0)
    {
       alert('Wrong');
        keys = [];
    }
}, true);

};

Any help would be greatly appreciated.

I am trying to create a .js file for a website that upon entering the konami code Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start(enter) it will embed a video. However while entering the right keys the webpage should display something like "keep going", if a wrong key is entered it should display "wrong, try again", and allow them to start over.

I've manged to get the JavaScript working where upon entering the right code it displays an alert, and entering the wrong code displays a different code.

i've manged to get this much code using online resources but none of them explain how to get wrong, try again part

    if (window.addEventListener) {
    var keys = [],
    konami = "38,38,40,40,37,39,37,39,66,65,13";

    window.addEventListener("keydown", function(e){
    keys.push(e.keyCode);


    if (keys.toString().indexOf(konami) >= 0) 
    {            
       alert('Right');
        keys = [];
    };

    if (keys.toString().indexOf(konami) < 0)
    {
       alert('Wrong');
        keys = [];
    }
}, true);

};

Any help would be greatly appreciated.

• javascript

4 Answers 4

if (window.addEventListener) {
    var index = 0;
    var konami = [38,38,40,40,37,39,37,39,66,65,13];

    window.addEventListener("keydown", function(e){
        if (e.keyCode === konami[index])
        {
            index++; //valid key at the valid point

            if (index == konami.length)
            {
                alert("Correct");
            } else {
                alert("Keep going");
            }
        } else {
            // incorrect code restart
            index = 0;
            alert("Wrong"); 
        }
   });
}

You could do something like

 if (window.addEventListener) {
    var keys = [],
    konami = "38,38,40,40,37,39,37,39,66,65,13".split(',');

    window.addEventListener("keydown", function(e){
    keys.push(e.keyCode);
        console.log(e.keyCode);
    var lengthOfKeys = keys.length -1;


    if (konami[lengthOfKeys] == keys[lengthOfKeys])
    {            
       alert('Right');
        if(konami.length === keys.length){
            alert('plete!');
        }

    }else{
       alert('Wrong');
        keys = [];
    }
}, true);
};

fiddle here http://jsfiddle/b6kuZ/

This works for me:

if (window.addEventListener) {
    var keys = [],
    konami = "38,38,40,40,37,39,37,39,66,65,13";
    konami_arr = konami.split(',');

    window.addEventListener("keydown", function(e){
        keys.push(e.keyCode);

        var position = keys.length-1;

        if(keys[position ] != konami_arr[position])
        {
            alert('Wrong');
            keys = [];
        }
        else if (keys.join(',') == konami) 
        {            
           alert('Right');
            keys = [];
        };
    }, true);
}

​jsFiddle exmaple

Having an alert e up every time a key is hit is very jarring. Instead, why mot have the validation of correct answers show up in a DIV, and only use an alert when the answer is incorrect.

     function checker(){

     if (kc==11){

        kc=0;  // This resets the sequence. 

        // The function for what you want to occur goes here. 
      }
     }

     function keyUp(e) {
 var keynum;
        if (window.event){keynum = event.keyCode;}
 else if (e.which){keynum = e.which;}
     for (i=0;i<222;i++){

// The 222 represents all the keys on the keyboard.

     var kx=konamicode[kc]; // kx represents the current position in the code sequence.

     var res=document.getElementById('response');
     var dumb=wrong[kc];

      if (keynum==i){

 // Checks to see if key matches sequence,  and resets sequence if it doesn't.

      if (i!=kx){
                 res.innerHTML='';
                 alert(dumb); // Reprimands user, and resets the sequence.
                 kc=0;
                 } 
             else {
             res.innerHTML=right[kc];   // Congratulates user, and advances the sequence.
             kc++;
             }

       }
     }
   checker();
       }

document.onkeyup = keyUp;

In the body of the page you will need to put a DIV to display that key strokes were validated as correct.

<div id="response"></div>