How to create a JavaScript code for multiple keys pressed at once?

Use the keydown event in JavaScript to get to know which keys are pressed at once. The following is the script −

Example

var log = $('#log')[0],
   keyPressed = [];

$(document.body).keydown(function (evt) {
   var li = keyPressed [evt.keyCode];
   if (!li) {
      li = log.appendChild(document.createElement('li'));
      keyPressed [evt.keyCode] = li;
   }
   $(li).text(Key Down: ' + evt.keyCode);
   $(li).removeClass('key-up');
});

$(document.body).keyup(function (evt) {
   var li = keyPressed [evt.keyCode];
   if (!li) {
      li = log.appendChild(document.createElement('li'));
   }
   $(li).text('Key Up: ' + evt.keyCode);
   $(li).addClass('key-up');
});