这是在两种不同类型的数组之间进行转换的最佳方法吗？

Question

I need to convert array like this

array(
    0=>array("key"=>"key1", "val"=>"val1"),
    1=>array("key"=>"key2", "val"=>"val2"),
    2=>array("key"=>"key3", "val"=>"val3"),
)

To array like this

array(
  "key1"=>"val1",
  "key2"=>"val2",
  "key3"=>"val3",
)

I do like below:

foreach($oldArray as $element){
    $newArray[$element["key"]] = $element["val"];
}

Is this the best way to convert these arrays? (Especially if the array is huge.)

Answer 1

The least memory consuming way would be to use generators. Something like this should work, but I haven't tested it.

function flatten(array $inArray) {
  foreach($inArray as $subArray) {
    yield $subArray['key'] => $subArray['val'];
  }
}

$newArray = iterator_to_array(flatten($oldArray));

Note: You need PHP 5.5+ for this.

Answer 2

Yes, the best way is using a foreach, even if your array is huge, that's not take many time.

Is your code working now? Else I can help you.

Answer 3

You can tell php to use foreach on their own like below.

$array = array(
        0=>array("key"=>"key1", "val"=>"val1"),
        1=>array("key"=>"key2", "val"=>"val2"),
        2=>array("key"=>"key3", "val"=>"val3"),
    );
    $result = array();
    array_walk($array, function($value) use (&$result) {
            $result[$value['key']] = $value['val'];
        }); 

    echo '<pre>';
    print_r($result);
    echo '</pre>';