How to disable repetitive keydown in jQuery [duplicate]

Answer 1

Keep track of which keys are down, and ignore keycode 39 until a keyup even clears it:

var down = {};

$(document).keydown(function(event){
     var keycode = (event.keyCode ? event.keyCode : event.which);
     if(keycode == '39'){
          if (down['39'] == null) { // first press
              $("#box").animate({"left": "+=30px"}, "fast");
              down['39'] = true; // record that the key's down
          }
     } 
   });

$(document).keyup(function(event) {
     var keycode = (event.keyCode ? event.keyCode : event.which);
     down[keycode] = null;
});

Answer 2

keep a flag and turn it green upon keydown i would suggest keyup though

$(document).keydown(function(event){
     $flag=false;
     var keycode = (event.keyCode ? event.keyCode : event.which);

      if(keycode == '39'){
           if(!$flag){
              $flag=true;
              $("#box").animate({"left": "+=30px"}, "fast");
      }
     } 
   });