在多维数组中删除重复项，并保留原始数组键值

Question

I have this array

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)
)

我希望最终结果如下：

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，在转换后，数组键值必须相同。 目前我使用这个解决方案：

$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;

这会去掉重复的数组，但是也会重置键值。

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)
)

如何保留原始数组键值？

- RaduS

Answer 1

请在foreach()中使用可选的$key参数：

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

http://codepad.org/SuClGlQW

Outputs:

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
        )

)

- Jared Farrish

---

谢谢@JaredFarrish。我会接受您的回答作为正确答案 :) - RaduS

Answer 2

你只需要使用 unset 函数即可。 unset 函数可以在不重新排列数组索引的情况下从指定索引中删除数组项。

代码如下：

$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"];
}

"and the output will be as follows"（并且输出将如下所示）

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)
  }
}

- Bahaa Galal

---

这段代码的返回值只会是名称，而不是数组。 - Balalen