公告：未定義的索引：在類 - >陣列

Question

這是代碼：

class app { 
    public $conf = array(); 
    public function init(){ 
     global $conf; 
     $conf['theme'] = 'default'; 
     $conf['favicon'] = 'favicon.ico'; 
    } 
    public function site_title(){ 
     return 'title'; 
    } 
} 

$app = new app; 
$app->init(); 


//output 
echo $app->conf['theme']; 

而且我得到這個錯誤：

Notice: Undefined index: theme in C:\xampp\htdocs\...\trunk\test.php on line 21 

我在哪裏出了問題，並沒有任何簡單的方法獲得相同的結果？

Answer 1

您在OOP的精彩世界，不再做你必須使用global！

試試這個：

class app 
{ 
    public $conf = array(); 

    // Notice this method will be called every time the object is isntantiated 
    // So you do not need to call init(), you can if you want, but this saves 
    // you a step 
    public function __construct() 
    {  
     // If you are accessing any member attributes, you MUST use `$this` keyword 
     $this->conf['theme'] = 'default'; 
     $this->conf['favicon'] = 'favicon.ico'; 
    } 
} 

$app = new app; 

//output 
echo $app->conf['theme']; 

Answer 2

您正在填充單獨的全局變量而不是對象屬性。使用$this：

class app { 
    public $conf = array(); 
    public function init(){ 
     $this->conf['theme'] = 'default'; 
     $this->conf['favicon'] = 'favicon.ico'; 
    } 
    public function site_title(){ 
     return 'title'; 
    } 
} 
$app = new app; 
$app->init(); 

//output 
echo $app->conf['theme'];