"Cannot read property 'xxx' of null"

javascript null typeerror
Matrym picture Matrym · Apr 26, 2010 · Viewed 52.2k times · Source

I've got a document fragment with children that I want to loop over (when possible). This is causing an error "Cannot read property 'xxx' of null".

How do I test if this will be the case?

Answer

Daniel Vassallo picture Daniel Vassallo · Apr 26, 2010

You may want to do the following: 

if ((documentFragment !== null) && documentFragment.hasOwnProperty('xxx')) {
    // handle property xxx of documentFragment as required
}

Related questions

How can I check for an empty/undefined/null string in JavaScript?

I saw this question, but I didn't see a JavaScript specific example. Is there a simple string.Empty available in JavaScript, or is it just a case of checking for ""?

Read More
How can I determine if a variable is 'undefined' or 'null'?

How do I determine if variable is undefined or null? My code is as follows: var EmpName = $("div#esd-names div#name").attr('class'); if(EmpName == 'undefined'){ // DO SOMETHING }; <div id="esd-names"> <div id="name"></div&…

Read More
Is there a standard function to check for null, undefined, or blank variables in JavaScript?

Is there a universal JavaScript function that checks that a variable has a value and ensures that it's not undefined or null? I've got this code, but I'm not sure if it covers all cases: function isEmpty(val){ return (val === …

Read More