Why does this code not work?

var all_obj_element= new Array();
all_obj_element[0]= document.getElementById('Img3');            
alert(all_obj_element[0].style.width);

The alert shows an empty box!

Why does this code not work?

var all_obj_element= new Array();
all_obj_element[0]= document.getElementById('Img3');            
alert(all_obj_element[0].style.width);

The alert shows an empty box!

• javascript

• Did you try .width instead of style.width ? – mplungjan Commented May 26, 2011 at 6:23

3 Answers 3

Because you haven't set the width. Here is how you get the puted style value of an element:

var putedStyle = function (el,style) {
    var cs;
    if (typeof el.currentStyle != 'undefined'){
        cs = el.currentStyle;
    }
    else {
        cs = document.defaultView.getComputedStyle(el,null);
    }
    return  cs[style];
}

Now let's get the value:

var element = document.getElementById('Img3');

alert(putedStyle(element,'width'));

The element with the id Img3 has not had its .style.width property set (which can be done by assigning a value to it via JavaScript, or by using the style attribute).

Quirks Mode has an article on how to read the puted style in a cross-browser fashion.

If there is no need to see the STYLEd width, just look at the width:

var all_obj_element= [];
all_obj_element[0]= document.getElementById('Img3');            
alert(all_obj_element[0].width);