Question

79

if function does not exist write function - javascript

rated 0 times [ 81] [ 2] / answers: 1 / hits: 15723 / 13 Years ago, thu, january 12, 2012, 12:00:00

In php I'm writing the following

<?php

if(x != 0) {

echo function myfunction(){};;    

}

?>

In javascript I wish to test if the function exists and if not write out an empty function

if(typeof myfunction != 'function'){

    function myfunction(){};

}

This works great in firefox but, in chrome even if the typeof equals function it still goes into and creates the empty function. I can't find a work around for chrome, i've tried if(!myfunction), if(typeof window.myfunction != 'function) but nothing seems to work here for chrome when everything seems to work in firefox. Any ideas?

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

jayla

Add To Favorites

Follow

Total Points: 14

Total Questions: 96

Total Answers: 123

Location: Greenland

Member since Fri, Jul 31, 2020

4 Years ago

answered 13 Years ago sonja · Accepted Answer

Use a function expression, not a function declaration.

if(typeof myfunction != 'function'){

   window.myfunction = function(){};

}

(I'm using window since your last paragraph suggests you want a global function)