如何使用eval（）调用PHP上的函数？

How can I call functions on PHP using eval()? is it possible? I wanna do something like this

<?php

$function1 = 'echo';
$function2 = 'implode';
$arr = array('arg1', 'arg2');

eval("$function1 ($function2(', ', $arr));");

?>

Or call other functions with multiple params? Is eval() what I'm looking for? Many thanks!

You don't need to eval anything:

$function1 = 'print';
$function2 = 'implode';
$arr = array('arg1', 'arg2');

$function1($function2(', ', $arr));

In fact, you can even use variable, variables:

$foo = 'print';
$bar = 'foo';

$$bar('hello');