laravel学习笔记（七）singleton和bind方法的区别

singleton和bind都是返回一个类的实例，不同的是singleton是单例模式，而bind是每次返回一个新的实例。

1、singleton

class fun {
    public $strKey;
}

app()->singleton('fun', fun::class);
$fun1 = app()->make('fun');
$fun2 = app()->make('fun');
$fun1->strKey = "fun1";
$fun2->strKey = "fun2";
echo $fun1->strKey . '  ' . $fun2->strKey;

　　最后获取到的结果是fun2 fun2

2、bind

class fun {
    public $strKey;
}

app()->bind('fun', fun::class);
$fun1 = app()->make('fun');
$fun2 = app()->make('fun');
$fun1->strKey = "fun1";
$fun2->strKey = "fun2";
echo $fun1->strKey . '  ' . $fun2->strKey;

　　最后获取到的结果是fun1 fun2

再看框架底层代码：

public function singleton($abstract, $concrete = null)
{
    $this->bind($abstract, $concrete, true);
}

发现singleton方法其实也是调用bind方法，只是最后一个参数是true，表示单例模式。框架源代码：Illuminate/Container/Container.php