Javascript function call by string name

Question

I have a javascript function defined like this

function is_mandatory(string){
     if(string.length > 0 )
 return true;   
}

Now, i am trying to call the function defined as a sting name

var is_mandatory; 

is_mandatory("Check");

But, this returns an error saying variable is not a function. How can I call the function from a string name.

Cheers!

You have defined variable with same name as method and that's why you are getting such an error. Try changing variable name of `var is_mandatory;`. — Harry Joy, Dec 05 '11 at 06:08
You're not trying to call the function defined as a string name. — Dave Newton, Dec 05 '11 at 06:09
possible duplicate of [How to execute a JavaScript function when I have its name as a string](http://stackoverflow.com/questions/359788/how-to-execute-a-javascript-function-when-i-have-its-name-as-a-string) — Strelok, Dec 05 '11 at 06:12
Your definition of is_mandatory will return `undefined` if you pass in a string whose length === 0. I don't think this is intended. — helpermethod, Dec 05 '11 at 07:41

OnesimusUnbound · Answer 1 · 2011-12-05T06:16:51.213

2

This will work.

function is_mandatory(str){
     return (str.length > 0 );
}

is_mandatory("Check");

You do not have to declare var for is_mandatory

edited Dec 05 '11 at 06:16

answered Dec 05 '11 at 06:10

OnesimusUnbound

Blender · Answer 2 · 2011-12-05T06:14:12.563

0

You are re-defining is_mandatory as an undefined variable when you run this code:

var is_mandatory;

But I don't think that is your intent. Just delete that var line completely.

edited Dec 05 '11 at 06:14

answered Dec 05 '11 at 06:06

Blender

No problem. They are similar concepts, just different actual values. – Alex Wayne Dec 05 '11 at 07:35

score 0 · Answer 3 · answered Dec 05 '11 at 06:09

0

If your variable is declared in the window's scope you can do this:

function is_mandatory(str){
    if(window[str].length > 0 )
        return true;   
}

answered Dec 05 '11 at 06:09

Paul

score -2 · Answer 4 · answered Dec 05 '11 at 06:09

-2

Initialize you variable with your function, and then try to call it.

var is_mandatory = is_mandatory;

is_mandatory("Check");

answered Dec 05 '11 at 06:09

Andrey Selitsky

4 Answers4