Is there any way to call a function by another function argument?

Question

I have two JavaScript function. I want to call a function by another function argument. Like this code:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv='Content-type' content='text/html; charset=utf-8'>
    <title>Javascript Function</title>
    <script language="javascript" type="text/javascript">
        function fOne()
        {
            alert("Function One");
        }
        function fTwo(f_name)
        {
            f_name; // I want to Call fOne() here
        }
    </script>
</head>
<body>
    <a href="#" onclick="fTwo('fOne')">Call Function</a>
</body>
</html>

Is this posible in any way?

just replace f_name; with fOne(); – Gar Oct 12 '13 at 15:33 — Gar, Oct 12 '13 at 15:33

score 4 · Answer 1 · answered Oct 12 '13 at 15:34

4

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv='Content-type' content='text/html; charset=utf-8'>
    <title>Javascript Function</title>
    <script language="javascript" type="text/javascript">
        function fOne()
        {
            alert("Function One");
        }
        function fTwo(f_name)
        {
            f_name(); // I want to Call fOne() here
        }
    </script>
</head>
<body>
    <a href="#" onclick="fTwo(fOne)">Call Function</a>
</body>
</html>

This is all that you need

answered Oct 12 '13 at 15:34

Akshay Khandelwal

1,570
11
19

1

Additionally, check out the "call" and "apply" methods -- they let you set the "this" object, and "apply" lets you pass an array to represent all the arguments (for when you don't know at code-time how many arguments there will be). – Max Oct 12 '13 at 15:36

score 3 · Accepted Answer · edited May 23 '17 at 12:21

3

You can do this:

function one() {
    alert('one');
}

function two(fname) {
    window[fname]();
}

two('one');

For a more complete answer, see here: How to execute a JavaScript function when I have its name as a string

edited May 23 '17 at 12:21

Community

1
1

answered Oct 12 '13 at 15:39

Tom Macdonald

6,433
7
39
59

score 1 · Answer 3 · answered Oct 12 '13 at 15:35

Try like this:-

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv='Content-type' content='text/html; charset=utf-8'>
    <title>Javascript Function</title>
    <script language="javascript" type="text/javascript">
        function fOne()
        {
            alert("Function One");
        }
        function fTwo(f_name)
        {
            f_name(); // I want to Call fOne() here
        }
    </script>
</head>
<body>
    <a href="#" onclick="fTwo(fOne)">Call Function</a>
</body>
</html>

score 1 · Answer 4 · answered Oct 12 '13 at 15:38

The best way to do this is to pass a reference to your function (fOne) and not a string (other answers are already covering this). However, if you really want to call your function by its name, you can look it up in the window object:

function fOne(){ console.log("fOne"); }
function fCall (f_name) { 
    window[f_name]();
}

fCall("fOne"); // results in console.log.

However, stringly code tends to be more error prone, so use the method provided by Akshay or Rahul instead.

score -1 · Answer 5 · answered Oct 12 '13 at 15:33

-1

function fTwo(f_name)
{
    eval(f_name+"()");
}

I'll let someone cleverer than I explain the security implications.

answered Oct 12 '13 at 15:33

Hans Z

4,664
2
27
50

Evil!! Eaval is Evil!! – Akshay Khandelwal Oct 12 '13 at 15:34
1

someone like @AkshayKhandelwal – Hans Z Oct 12 '13 at 15:34

Is there any way to call a function by another function argument?

5 Answers5