A function inside an if structure

Question

can I put a function in PHP inside a if structure? like this:

<?php
    if(true){
         function HelloWorld(){
             echo "Hello World!!!";
         }
         HelloWorld();
    }
?>

because I have tried and it works, but I don't know if it is correct or not. Thanks

Answer 1

This is perfectly legal - it simply defines the function within the if statement block. That said, quite why you'd want to do this is somewhat of a mystery.

It's also worth noting that this function will be available in the global scope (i.e.: outside of the if statement block), as...

All functions and classes in PHP have the global scope - they can be called outside a function even if they were defined inside and vice versa.

See the PHP User-defined functions manual page for more information.

Answer 2

As middaparka says, this is perfectly legal, but in terms of using it, you might want to check if a function exists before declaring it:

if (!function_exists("foo"))
{
    function foo()
    {
        return "bar";
    }
}

• function_exists documentation