PHP脚本中类名冲突的解决方案与最佳实践

<?php
// script_one.php
class foo {
    public function do_something() {
        echo "Doing something from script one.
";
    }
}

$foo_instance_one = new foo();
$foo_instance_one->do_something();
?>

<?php
// script_two.php
class foo {
    public function do_something_two() {
        echo "Doing something two from script two.
";
    }
}

$foo_instance_two = new foo();
$foo_instance_two->do_something_two();
?>

<?php
// master_script.php
require('script_one.php');
require('script_two.php'); // 这将导致致命错误：Cannot redeclare class foo
?>

<?php
// script_one.php
class FooBase { // 将类名改为 FooBase
    public function do_something() {
        echo "Doing something from FooBase (script one).
";
    }
}
?>

<?php
// script_two.php
class Foo extends FooBase { // Foo 类继承 FooBase
    public function do_something_two() {
        echo "Doing something two from Foo (script two).
";
    }
}
?>

<?php
// master_script.php
require('script_one.php');
require('script_two.php');

$foo_instance = new Foo(); // 实例化派生类 Foo
$foo_instance->do_something();     // 调用基类 FooBase 的方法
$foo_instance->do_something_two(); // 调用派生类 Foo 自己的方法
?>

Doing something from FooBase (script one).
Doing something two from Foo (script two).

<?php
// script_one.php
namespace AppModuleOne; // 定义命名空间 AppModuleOne

class Foo {
    public function do_something() {
        echo "Doing something from App\ModuleOne\Foo.
";
    }
}
?>

<?php
// script_two.php
namespace AppModuleTwo; // 定义命名空间 AppModuleTwo

class Foo {
    public function do_something_two() {
        echo "Doing something two from App\ModuleTwo\Foo.
";
    }
}
?>

<?php
// master_script.php
require('script_one.php');
require('script_two.php');

// 使用 use 语句导入命名空间中的类，并可以为其设置别名
use AppModuleOneFoo as FooOne;
use AppModuleTwoFoo as FooTwo;

// 或者直接使用完全限定名称
// $foo_instance_one = new AppModuleOneFoo();
// $foo_instance_two = new AppModuleTwoFoo();

$foo_instance_one = new FooOne();
$foo_instance_one->do_something();

$foo_instance_two = new FooTwo();
$foo_instance_two->do_something_two();
?>

Doing something from AppModuleOneFoo.
Doing something two from AppModuleTwoFoo.