Question

Suppose I have a div named container as shown

<div id='container'>50</div>

Now if I use

var a = document.getElementById('container').value;
var b = document.getElementById('container1').value;

Here a, is fine but b gives an error

SO, is there any way to check whether a div is present or not, if, its there, I will obtain its value

Answer 1

document.getElementById will return undefined if no element is found on the page. So, you can explicitly check for undefined before trying to access the value.

var element = document.getElementById('container1');
if (element != undefined) //note: this can be shortened to just "if (element)"
{
    alert(element.value);
}