How do I call a function using a function name generated from a string variable

Question

In the process of automating some code, I am looking to call upon a function based on what a string is.

For example, I have a variable $somevar which is set to the string "This". Now I want to run a function doThis();

So, I was hoping I could write do.$somevar($var,$var2) . I want it to run doThis($var1,$var2).

Is this possible?

are the range of possibilities for $somevar known and limited or unknown and unlimited? — Drew
– Drew, Commented Apr 7, 2010 at 6:24

MiffTheFox · Accepted Answer · 2010-04-07 06:44:39Z

4

You can use call_user_func to accomplish this.

call_user_func("do" . $somevar, $var1, $var2);

You can also use is_callable to check for error conditions.

if (is_callable("do" . $somevar)) {
    call_user_func("do" . $somevar, $var1, $var2);
} else {
    echo "Function do" . $somevar . " doesn't exist.";
}

edited Apr 7, 2010 at 6:44

answered Apr 7, 2010 at 6:27

MiffTheFox

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2 Comments

ChrisR Over a year ago

As far as i know call_user_func works on any callable function, even built in php functions like strtoupper, sprintf, ...

MiffTheFox Over a year ago

@ChrisRamakers You're right, thank you for pointing this out.

Tom Haigh · Accepted Answer · 2010-04-07 07:28:28Z

3

I don't think you can do it like that, but you could do:

call_user_func('do'. $somevar, $var, $var2);

or

$func = 'do' . $somevar;
$func($var, $var2);

edited Apr 7, 2010 at 7:28

answered Apr 7, 2010 at 6:27

Tom Haigh

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Comments

ChrisR · Accepted Answer · 2010-04-07 06:27:32Z

1

This is perfectly legal in php

$myVar = 'This';

$method = 'do'.$myVar; // = doThis
$class  = new MyClass();
$class->$method($var1, $var2, ...); // executes MyClass->doThis();

answered Apr 7, 2010 at 6:27

ChrisR

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Comments

Your Common Sense · Accepted Answer · 2010-04-07 06:28:20Z

1

$fname="do$somevar";
$fname();

But you should think twice before using it.

answered Apr 7, 2010 at 6:28

Your Common Sense

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Comments

martin · Accepted Answer · 2010-04-07 07:43:13Z

0

check call_user_func or call_user_func_array

class myclass {
    static function say_hello()
    {
        echo "Hello!\n";
    }
}

$classname = "myclass";

call_user_func(array($classname, 'say_hello'));
call_user_func($classname .'::say_hello'); // As of 5.2.3

answered Apr 7, 2010 at 7:43

martin

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Comments

aviv · Accepted Answer · 2010-04-07 07:50:50Z

0

In php you use -> instead of . this will work:

$foo = new someObject;
$somevar = 'function_name';
$foo->$somevar('x');

edited Apr 7, 2010 at 7:50

answered Apr 7, 2010 at 6:25

aviv

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1 Comment

kibibu Over a year ago

I think Roeland was using the . as the string concatenation operator

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