访问父函数中定义的变量

Question

Is there a way to access $foo from within inner()?

function outer()
{
    $foo = "...";

    function inner()
    {
        // print $foo
    }

    inner();
}

outer();

Answer 1

PHP<5.3 does not support closures, so you'd have to either pass $foo to inner() or make $foo global from within both outer() and inner() (BAD).

In PHP 5.3, you can do

function outer()
{
  $foo = "...";
  $inner = function() use ($foo)
  {
    print $foo;
  };
  $inner();
}
outer();
outer();