PHP多維數組類型提示功能參數

Question

在PHP中，是否可以鍵入提示多維數組作爲函數參數？

當然，你可以鍵入提示單個陣列這樣：

function Example(array $parameter) {} 

但是，如果一個函數需要的參數是一個多維數組有沒有辦法通過類型提示強制執行呢？

Answer 1

如果按DoubleArray您的意思只是一個雙數組（浮點數）。然後你可能想用自定義類來僞造它。考慮下面的代碼。請注意，最初的Array包含strings但最終結果不會：

<?php 

    class DoubleArray{ 
     protected $instance; 
     public function __construct(array $arrDoubles) { 
      foreach($arrDoubles as $key=>$double) { 
       if(!is_double($double)){ 
        unset($arrDoubles[$key]); 
       } 
      } 
      $this->instance = array_values($arrDoubles); 
     } 

     public function push($numDouble){ 
      $this->instance[] = $numDouble; 
     } 

     public function get(){ 
      return $this->instance; 
     } 
    } 

    $arr = array(2.35, 72.9, 88.45, 42.76, "No...", 57.77, "String is not Double"); 
    $da  = new DoubleArray($arr); 

    var_dump(getData($da)); 


    function getData(DoubleArray $data){ 
     // ALL ARRAY FUNCTIONS STILL APPLY TO THE $doubleArray VARIABLE 
     // HOWEVER TO GET THE CUSTOM DOUBLE ARRAY DATA, YOU MAY HAVE TO 
     // JUST CALL THE get() METHOD ON THE DoubleArray INSTANCE: $data 
     $doubleArray = $data->get(); 
     return $doubleArray; 
    } 

    // THE var_dump(getData($da); ABOVE PRODUCES: 
    array (size=5) 
     0 => float 2.35 
     1 => float 72.93 
     2 => float 88.45 
     3 => float 42.76 
     4 => float 57.77 

然而，如果 DoubleArray你的意思 Multidimensional Arrays，你仍然可以使用它自定義類，如下圖所示假貨。

<?php 

    class DoubleArray{ 
     protected $instance; 

     public function __construct(array $arrMDDoubles) { 
      foreach($arrMDDoubles as $key=>$subArray) { 
       if(!is_array($subArray)){ 
        throw new Exception("DoubleArray accepts only Multidimensional Arrays..."); 
       } 
      } 
      $this->instance = $arrMDDoubles; 
     } 

     public function push($arrArray, $key=null){ 
      if(!is_array($arrArray)){ 
       throw new Exception("You can only Push an Array..."); 
      } 
      if(!is_null($key)){ 
       $this->instance[$key] = $arrArray; 
      }else{ 
       $this->instance[]  = $arrArray; 
      } 
      return $this; 
     } 

     public function get(){ 
      return $this->instance; 
     } 
    } 

    $arr = array(array(2.35, 72.93,), array(88.45, 42.76), array("No...", 57.77, "String is not Double")); 
    $da  = new DoubleArray($arr); 

    var_dump(getData($da)); 


    function getData(DoubleArray $data){ 
     // ALL ARRAY FUNCTIONS STILL APPLY TO THE $doubleArray VARIABLE 
     // HOWEVER TO GET THE CUSTOM DOUBLE ARRAY DATA, YOU MAY HAVE TO 
     // JUST CALL THE get() METHOD ON THE DoubleArray INSTANCE: $data 
     $doubleArray = $data->get(); 
     return $doubleArray; 
    } 

    // THIS TIME THE THE var_dump(getData($da) ABOVE WOULD THROW AN EXCEPTION 
    // IF THE GIVEN ARRAY IS NOT MULTI-DIMENSIONAL BUT PRODUCE SOMETHING 
    // LIKE THIS OTHERWISE:  
    array (size=3) 
     0 => 
     array (size=2) 
      0 => float 2.35 
      1 => float 72.93 
     1 => 
     array (size=2) 
      0 => float 88.45 
      1 => float 42.76 
     2 => 
     array (size=3) 
      0 => string 'No...' (length=5) 
      1 => float 57.77 
      2 => string 'String is not Double' (length=20)