How to add konami code in a website based on html?
compact version:
function onKonamiCode(cb) {
var input = '';
var key = '38384040373937396665';
document.addEventListener('keydown', function (e) {
input += ("" + e.keyCode);
if (input === key) {
return cb();
}
if (!key.indexOf(input)) return;
input = ("" + e.keyCode);
});
}
onKonamiCode(function () {alert('\o/')})Place the code below in a file js/konami.js and reference it in the body of your html file like this: <script src="js/konami.js"></script>
// a key map of allowed keys
var allowedKeys = {
37: 'left',
38: 'up',
39: 'right',
40: 'down',
65: 'a',
66: 'b'
};
// the 'official' Konami Code sequence
var konamiCode = ['up', 'up', 'down', 'down', 'left', 'right', 'left', 'right', 'b', 'a'];
// a variable to remember the 'position' the user has reached so far.
var konamiCodePosition = 0;
// add keydown event listener
document.addEventListener('keydown', function(e) {
// get the value of the key code from the key map
var key = allowedKeys[e.keyCode];
// get the value of the required key from the konami code
var requiredKey = konamiCode[konamiCodePosition];
// compare the key with the required key
if (key == requiredKey) {
// move to the next key in the konami code sequence
konamiCodePosition++;
// if the last key is reached, activate cheats
if (konamiCodePosition == konamiCode.length) {
activateCheats();
konamiCodePosition = 0;
}
} else {
konamiCodePosition = 0;
}
});
function activateCheats() {
document.body.style.backgroundImage = "url('images/cheatBackground.png')";
var audio = new Audio('audio/pling.mp3');
audio.play();
alert("cheats activated");
}EDIT: changed the sequence to b, a instead of a, b. Thanks for the comment!
EDIT 2: reset the konamiCodePosition to 0 after activateCheats was called. Thanks for the comment!
My own compact and cleaned version inspired by the answers here:
let cursor = 0;
const KONAMI_CODE = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65];
document.addEventListener('keydown', (e) => {
cursor = (e.keyCode == KONAMI_CODE[cursor]) ? cursor + 1 : 0;
if (cursor == KONAMI_CODE.length) activate();
});
In this case, the activate() function is called when triggered.