CODEWITHSUNDEEP
jqueryfunction
user1995781
user1995781

Reputation: 19463

jQuery isFunction check error "function is not defined"

I want to do a check whether a function exist or not before trying to run it. Here is my code:

if ($.isFunction(myfunc())) {
    console.log("function exist, run it!!!");
}

However, when the function is not available I got the error:

myfunc is not defined

How can I do the detection? Here is my working test: http://jsfiddle.net/3m3Y3/

Upvotes: 50

Views: 75984

Answers (2)

Ihsahs
Ihsahs

Reputation: 902

try this

if(typeof myfunc == 'function'){
    alert("exist");
}else{
    alert("not exist");
}

Upvotes: 13

jcsanyi
jcsanyi

Reputation: 8174

By putting () after the function name, you're actually trying to run it right there in your first line.

Instead, you should just use the function name without running it:

if ($.isFunction(myfunc)) {

However - If myfunc is not a function and is not any other defined variable, this will still return an error, although a different one. Something like myfunc is not defined.

You should check that the name exists, and then check that it's a function, like this:

if (typeof myfunc !== 'undefined' && $.isFunction(myfunc)) {

Working example here: http://jsfiddle.net/sXV6w/

Upvotes: 138

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