PHP命名空间namespace定义及导入use用法详解

<?php
echo 111;  //由于namespace前有代码而报错
namespace Teacher;
class Person{
  function __construct(){
   echo 'Please study!';
  }
}

<?php
namespace Teacher;
class Person{
  function __construct(){
   echo 'Please study!<br/>';
  }
}
function Person(){
  return 'You must stay here!';
};
namespace Student;
class Person{
  function __construct(){
   echo 'I want to play!<br/>';
  }
}
new Person();     //本空间（Student空间）
new \Teacher\Person();   //Teacher空间
new \Student\Person();   //Student空间
echo \Teacher\Person();   //Teacher空间下Person函数

I want to play!
Please study!
I want to play!
You must stay here!

<?php  //1.php
class Person{
 function __construct(){
   echo 'I am one!<br/>';
  }
}

<?php
namespace Newer;
require_once './1.php';
new Person();  //报错，找不到Person;
new \Person();  //输出 I am tow!;

<?php  //2.php
namespace Two
class Person{
 function __construct(){
   echo 'I am tow!<br/>';
  }
}

<?php
namespace New;
require_once './2.php';
new Person();  //报错，(当前空间)找不到Person;
new \Person();  //报错，(公共空间)找不到Person;
new \Two\Person(); //输出 I am tow!;

namespace School\Parents;
class Man{
  function __construct(){
   echo 'Listen to teachers!<br/>';
  }
}
namespace School\Teacher;
class Person{
  function __construct(){
   echo 'Please study!<br/>';
  }
}
namespace School\Student;
class Person{
  function __construct(){
   echo 'I want to play!<br/>';
  }
}
new Person();     //输出I want to play!
new \School\Teacher\Person(); //输出Please study!
new Teacher\Person();   //报错
----------
use School\Teacher;
new Teacher\Person();   //输出Please study!
----------
use School\Teacher as Tc;
new Tc\Person();   //输出Please study!
----------
use \School\Teacher\Person;
new Person();   //报错
----------
use \School\Parent\Man;
new Man();   //报错