对象实例化PHP类的本地范围还是全局范围？

Question

在为网站编写PHP代码时，更好的是：

<?php

  include ("myclass.php");
  $theClass = new MyClass();

  function x () {
    global $theClass;
    $theClass->theProperty="foo";
    $theClass->doStuff();
  }

  function y () {
    global $theClass;
    $theClass->theProperty="bar";
    $theClass->doStuff();form
  }

?>

或者：

<?php

  include ("myclass.php");

  function x () {
    $theClass = new MyClass();
    $theClass->theProperty="foo";
    $theClass->doStuff ();
  }

  function y () {
    $theClass = new MyClass();
    $theClass->theProperty="bar";
    $theClass->doStuff ();
  }

?>

以上哪一个比较可取，对于$theClass的每个范围，有哪些优点和缺点？

Answer 1

更好的是下模 :^ )

  include ("myclass.php");

  function x (\MyClass $theClass) {
    $theClass->theProperty="foo";
    $theClass->doStuff ();
  }

  function y (\MyClass $theClass) {
    $theClass->theProperty="bar";
    $theClass->doStuff ();
  }

但这取决于..。*^)