javascript - javascript multiple keys pressed at once comes to error

Question

 $(document).keydown(function(e){
    var key=e.which;
    //to prevent reversing, add the possible value of d which hinders the snake to go to desired direction
    if(key=="37"&&d!="right"){
        if(p==true){
            clearInterval(game_loop);
            game_loop=setInterval(paint,60);
            p=false;
            d="left";
        }
        else{
            d="left";
        }
    }
    else if(key=="38"&&d!="down"){
        if(p==true){
            clearInterval(game_loop);
            game_loop=setInterval(paint,60);
            p=false;
            d="up";
        }
        else{
            d="up";
        }
    }
    else if(key=="39"&&d!="left"){
        if(p==true){
            clearInterval(game_loop);
            game_loop=setInterval(paint,60);
            p=false;
            d="right";
        }
        else{
            d="right";
        }
    }
    else if(key=="40"&&d!="up"){
        if(p==true){
            clearInterval(game_loop);
            game_loop=setInterval(paint,60);
            p=false;
            d="down";
        }
        else{
            d="down";
        }
    }
    else if(key=="32"){
        if(p==false){
            clearInterval(game_loop);
            p=true;
        }
        else{
            game_loop=setInterval(paint,60);
            p=false;
        }
    }
})

this code defines my keydown for my snake,. the problem is. whenever i pressed 2 keys at the same time or if i press down and left very quickly (perhaps other combinations are also possible) the game is over.,my function that checks the collision to its own body returns true after i press 2 keys quickly like down and left..

how can it be fixeD?

Answer 1

have you tried e.preventDefault() ..

$(document).keydown(function(e){
    var key=e.which;
    e.preventDefault();