How do I detect if a object has a certain property or not?

Question

I am trying to find a cross browser compatible way to find if a object has a certain property or not.

Eg. span

var elem = document.getElementById('span1');

if(elem.hasOwnProperty('title'))
{
}

this works in IE9 but throws nasty errors on IE8 and whole site is brought down just by this line. Is there any browser compatible way to find if object has certain property or not?

To clarify, you are talking specifically about _DOM_ objects? And when you say "property", do you mean "property" or "attribute"? — nnnnnn, Jun 22 '12 at 01:55

score 2 · Accepted Answer · answered Jun 22 '12 at 01:50

2

In this case, it's an HTML element so it would have a title attribute.

if(elem.getAttribute("title")) {...}

answered Jun 22 '12 at 01:50

Niet the Dark Absol

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I certainly hope so, given I've used it on every project I've ever made. – Niet the Dark Absol Jun 22 '12 at 01:53
@antisanity In this case, the only possible falsy value is an empty string, which you probably wouldn't want to do anything with anyway. Although it is something to look out for. – Niet the Dark Absol Jun 22 '12 at 01:57
`"0"` is truthy in JavaScript. – Niet the Dark Absol Jun 22 '12 at 02:00
Since OP listed a jQuery tag should probably mention `$(..).attr()`. While `getAttribute` is pretty safe there are some cases where it won't work at all, e.g `class` in ie6. – Jamie Treworgy Jun 22 '12 at 02:06

How do I detect if a object has a certain property or not?

1 Answers1