I try to assign "{transform: 'translateX(5px)'}" to a variable (called 'aa'). In order to add the pixel value of movement everytime a keydown function being triggered. But it won't work. Why?
I've tried something like this with: css()method and offset()method, they're all work, but why with this animate()method it didn't work?
<!DOCTYPE html>
<html>
<head>
<style>
    div.divx {
        width: 50px;
        height: 50px;
        background-color: black;
        position: absolute;
        left: 15px;
        top: 15px;
        z-index: -1;
    }
</style>
</head>
<body>
<div class="divx"></div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script>
    $(document).ready(function() {
        var i = 0;
        $(window).keydown(function(e) {
            if (e.which == 39) { //39 is right button
                i += 5;
                a = i + 'px';
                yy = 'translateX(' + a + ')';
                xx = '"' + yy + '"';
                aa = "{transform: " + xx + "}";
                alert(aa);
                $(".divx").animate(aa);
            }
        })
    })
</script>
</body>
</html>
 
     
    