laravel學習筆記（七）singleton和bind方法的區別

singleton和bind都是返回一個類的實例，不同的是singleton是單例模式，而bind是每次返回一個新的實例。

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;

　　最后獲取到的結果是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;

　　最后獲取到的結果是fun1 fun2

再看框架底層代碼：

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

發現singleton方法其實也是調用bind方法，只是最后一個參數是true，表示單例模式。框架源代碼：Illuminate/Container/Container.php