Question

For example I have the following code:

function a($param)
{
  function b()
  {
    echo $param;
  }
  b();
}
a("Hello World!");

That throws an E_NOTICE error because $param is of course undefined (in b()).

I cannot pass $param to b() because b() should be a callback function of preg_replace_callback().
So I had the idea to save $param in $GLOBALS.

Is there any better solution?

Answer 1

If you are using PHP 5.3, you could use anonymous function with use keyword instead:

<?php
function a($param)
{
  $b = function() use ($param)
  {
    echo $param;
  };

  $b();
}
a("Hello World!");