How to determine image height in jQuery?

Question

I tried the following code:

    var origh1 = $('img:first').height();
    alert(origh1);

But he warned the value "0".

My img tag has no height value, so it returns 0?

If so, how do I get the image height value?

In addition, I noticed that when I make an animation to increase the size of the image by 20% and reduce it by 20%, it becomes a little larger than the original. How to restore the original image size? And why doesn’t it return to the original if I reduce it by 20%. I know that Math is involved ... but how can I compensate for this in jQuery?

This is my code for this:

$('img:first').fadeIn('normal').delay(500).animate({'height':'+=20%'}, 1500, 'easeOutQuad')

And return to the original:

$('img:first').fadeIn('normal').animate({'height':'-=20%'}, 1000, 'swing');

Answer 1

, .

$(function() {
     alert( $('img').eq(0).height() )
});

, DOM Ready :

$(window).load(function() {
     alert( $('img').eq(0).height() )
});

Answer 2

Try

$(window).load(function(){
    $('img:first').attr("height")
});

edit - , . .