javascriptjquerynullinteger

JavaScript convert NULL to 0

I'm using jQuery to get the height of an element. But if the element doesn't exist, the following code will return NULL:

$height = $('#menu li.active ul').height(); // returns integer or null

Is it a cross-browser safe way for getting an integer value under every circumstance with the following code: 

$height = $('#menu li.active ul').height() + 0;
Solution

  • There are many ways to deal with this. The one you describe, adding an integer value to coerce the type is fine. You could also convert to a number explicitly:

    $height = Number($('#menu li.active ul').height());
// or:
$height = +$('#menu li.active ul').height();

    Or you could use a logical operator as null coerces to false:

    $height = $('#menu li.active ul').height() || 0;