getting the size of a content box with javascriptHey

Question

I am trying to get the width of my content box with the following comand:

var box = document.getElementById('player');
var boxSize = box.clientWidth;

It seems to return something. When I alert it it gives out a number. But it still throws the error:

Uncaught TypeError: Cannot read property 'clientWidth' of null

What is happening here?

perhaps your code is running before the element with ID has been rendered ... is the script above or below the element with that ID in the html document? — Jaromanda X, Aug 08 '16 at 09:35
@JaromandaX My javascript is called at the end of the html file. — Ipomea, Aug 08 '16 at 10:35

Syam Pillai · Accepted Answer · 2016-08-08T10:35:58.980

1

var box = document.getElementById('player');
if(box){
  var boxSize = box.offsetWidth;
}

edited Aug 08 '16 at 10:35

answered Aug 08 '16 at 09:37

Syam Pillai

How does it solves `Cannot read property of null`? – Justinas Aug 08 '16 at 10:27
offsetWidth gives the same error. – Ipomea Aug 08 '16 at 10:36
thanks. if(box) also works with var boxSize = box.clientWidth; – Ipomea Aug 08 '16 at 11:25

1 Answers1