PHP在另一个自定义函数中使用不同的自定义函

Question

I have created function

function do_stuff($text) {
   $new_text = nl2br($text);

   return $new_text;
}

$result = do_stuff("Hello 
 World!"); 
//returns "Hello <br /> World!"

I want to be able to supply another simple built in PHP function e.g. strtoupper() inside my function somehow, its not just strtoupper() that i need, i need ability to supply different functions into my do_stuff() function.

Say i want to do something like this.

$result = do_stuff("Hello 
 World!", "strtolower()");
//returns "Hello <br /> World!"

How would i make this work without creating another function.

function do_stuff($text, $sub_function='') {
   $new_text = nl2br($text);

   $sub_function($new_text);

   return $new_text;
}

$result = do_stuff("Hello 
 World!"); 
//returns "Hello <br /> World!"

P.S. Just remembered variable variables, and googled, there's actually is Variable functions too, might answer this one myself.

http://php.net/manual/en/functions.variable-functions.php

Answer 1

You have it in your second example. Just make sure to check that it exists and then assign the return to the string. There is an assumption here about what the function accepts/requires as args and what it returns:

function do_stuff($text, $function='') {
    $new_text = nl2br($text);

    if(function_exists($function)) {
        $new_text = $function($new_text);
    }
    return $new_text;
}

$result = do_stuff("Hello 
 World!", "strtoupper");