Jquery到Zoomin和Zoomout以及单击按钮时的图像形状

Question

I am working on Image upload and I need to add functionality to zoomin and zoomout and shapes (like landscape, portrait) of image on click of buttons. But nothing happens when I am clicking on the buttons. My code is:

$(document).ready(function() {

    var imagesize = $('img').width();
    alert(imagesize);
    $('#zoomout').on('click', function() {
        imagesize = imagesize - 5;
        $('img').width(imagesize);
    });

    $('#zoomin').on('click', function() {
        imagesize = imagesize + 5;
        $('img').width(imagesize);
    });

}); 

Answer 1

I guess you are missing the jQuery library:

<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script>
  $(document).ready(function() {
    var imagesize = $('img').width();
    alert(imagesize);
    $('#zoomout').on('click', function() {
        imagesize = imagesize - 5;
        $('img').width(imagesize);
    });

    $('#zoomin').on('click', function() {
        imagesize = imagesize + 5;
        $('img').width(imagesize);
    });
  });
</script>

Try adding a library first before this script.