JavaScript
Article
By Sam Deering

jQuery does function exist

By Sam Deering
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Checking if a function exists using JavaScript you can do the following:

if(typeof $form.validate == 'function')
{
    console.log('function is here!');
}
else
{
    console.log('function is absent... naughty!');
}

Example: Check if a the md5 function exists:

if(typeof window.md5 == 'function') {
    // function exists, so we can now call it
    md5(286);
}

And to check if a jQuery function exists:

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if( jQuery.isFunction(jQuery.fn.rtFunction) ){
  // function exists, so we can now call it
  jQuery(document).rtFunction();
}
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