刪除MultiDimensional數組中的重復項並保留原始數組鍵值

Question

我有這個數組

Array (
    [0] => Array ( [name] => Apple [amount] => 1)
    [1] => Array ( [name] => Apple [amount] => 2)
    [2] => Array ( [name] => Orange [amount] => 3)
    [3] => Array ( [name] => Orange [amount] => 4)
    [4] => Array ( [name] => Banana [amount] => 5)
    [5] => Array ( [name] => Pear [amount] => 6)
)

我最終會這樣結束：

Array (
    [0] => Array ( [name] => Apple [amount] => 1)
    [2] => Array ( [name] => Orange [amount] => 3)
    [4] => Array ( [name] => Banana [amount] => 5)
    [5] => Array ( [name] => Pear [amount] => 6)
)

重要的是轉換后數組鍵值必須相同。

目前我使用這個解決方案：

$newArray = array();
$usedFruits = array();

foreach ( $originalArray AS $line ) {
    if ( !in_array($line['name'], $usedFruits) ) {
        $usedFruits[] = $line['name'];
        $newArray[] = $line;
    }
}

$originalArray = $newArray;
$newArray = NULL;
$usedFruits = NULL;

這將刪除重復的數組，但它也會重置鍵值。

Array ( 
    [0] => Array ( [name] => Apple [amount] => 1)
    [1] => Array ( [name] => Orange [amount] => 3)
    [2] => Array ( [name] => Banana [amount] => 5)
    [3] => Array ( [name] => Pear [amount] => 6)
)

如何保留原始數組鍵值？

Answer 1

使用foreach()的可選$key ：

foreach ( $originalArray AS $key => $line ) { 
    if ( !in_array($line['name'], $usedFruits) ) { 
        $usedFruits[] = $line['name']; 
        $newArray[$key] = $line; 
    } 
} 

http://codepad.org/SuClGlQW

輸出：

Array
(
    [0] => Array
        (
            [name] => Apple
            [amount] => 1
        )

    [2] => Array
        (
            [name] => Orange
            [amount] => 3
        )

    [4] => Array
        (
            [name] => Banana
            [amount] => 5
        )

    [5] => Array
        (
            [name] => Pear
            [amount] => 6
        )

)

Answer 2

所有你必須使用的是未設置的功能。

unset函數從指定索引處的數組中刪除一個項而不重新設置數組索引。

代碼如下

$originalArray = array( 
    array("name" => "Apple", "amount" => 1),
    array("name" => "Apple", "amount" => 2),
    array("name" => "Orange", "amount" => 3),
    array("name" => "Orange", "amount" => 4),
    array("name" => "Banana", "amount" => 5),
    array("name" => "Peer", "amount" => 6)
);

$seenItems = array();

foreach($originalArray as $index => $item){
    if(in_array($item["name"], $seenItems))
        unset($originalArray[$index]);
    else
        $seenItems[] = $item["name"];
}

輸出如下

array(4) {
  [0]=>
  array(2) {
    ["name"]=>
    string(5) "Apple"
    ["amount"]=>
    int(1)
  }
  [2]=>
  array(2) {
    ["name"]=>
    string(6) "Orange"
    ["amount"]=>
    int(3)
  }
  [4]=>
  array(2) {
    ["name"]=>
    string(6) "Banana"
    ["amount"]=>
    int(5)
  }
  [5]=>
  array(2) {
    ["name"]=>
    string(4) "Peer"
    ["amount"]=>
    int(6)
  }
}