警告：array_keys（）預計參數1是陣列，NULL給出

Question

古怪的分析器錯誤：

Notice: Undefined property: template::$param in 
    C:\xampp\htdocs\app\includes\classes\class.template.php on line 37 

Warning: array_keys() expects parameter 1 to be array, null given in 
    C:\xampp\htdocs\app\includes\classes\class.template.php on line 37 

Notice: Undefined property: template::$param in 
    C:\xampp\htdocs\app\includes\classes\class.template.php on line 37 

Warning: array_values() expects parameter 1 to be array, null given in 
    C:\xampp\htdocs\app\includes\classes\class.template.php on line 37 

代碼：

public function newParam($trans, $value) { 
    $this->param['{' . $trans . '}'] = $value; 
} 

public function getParam($content) { 
    $content = str_replace(
     array_keys($this->param), 
     array_values($this->param), 
     $content 
    ); 

    return $content; 
} 

請注意，這不是任何現有的解析器。

Answer 1

初始化你的 「參數」：

function __construct() { 
    $this->param = array(); 
} 

您還可以看到PHP Doc

Creating/modifying with square bracket syntax 

An existing array can be modified by explicitly setting values in it. 

This is done by assigning values to the array, specifying the key in brackets. The key can also be omitted, resulting in an empty pair of brackets ([]). 

$arr[key] = value; 
$arr[] = value; 
// key may be an integer or string 
// value may be any value of any type