从二维数组的每一行中删除一列，并将其用作每行的新的一级键

Question

我想重写这个关联数组，并将键[unique_name]的值的级别切换到第一级别。有什么想法吗？

Array (
    [0] => Array (
        [value] => value1
        [name] => name1
        [unique_name] => unique1
    )
    [1] => Array (
        [value] => value2
        [name] => name2
        [unique_name] => unique2
    )
    [2] => Array (
        [value] => value3
        [name] => name3
        [unique_name] => unique3
    )
)

所需输出：

Array (
    [unique1] => Array (
        [value] => value1
        [name] => name1
    )
    [unique2] => Array (
        [value] => value2
        [name] => name2
    )
    [unique3] => Array (
        [value] => value3
        [name] => name3
    )
)

干杯， 阿德南

Answer 1

尝试以下循环：

// create an array to hold the new schema
$uniques = array();

// loop over all the records
foreach ($records as $record) {
    $uniques[$record['unique_name']] = $record;

    // remove the unique_name entry from the new array
    unset($uniques[$record['unique_name']]['unique_name']);
}

您可以轻松地在循环中执行硬编码键集，但如果稍后添加新索引，则可移植性会降低：

foreach ($records as $record) {
    $uniques[$record['unique_name']] = array(
        'name' => $record['name'],
        'value' => $record['value']
    );
}

Answer 2

$result = array();

foreach ($array as $entry) {
    $result[$array['unique_name']] = array_diff_key($entry, array_flip(array('unique_name')));
}

Answer 3

foreach($array as $item){
    $newarray[$item['unique_name']] = array('name' => $item['name'], 'value' => $item['value']);
}

Answer 4

只是为了好玩，使用带有闭包的 lambda 函数的版本：

$input = Array (
    Array ("value" => "value1", "name" => "name1", "unique_name" => "unique1"),
    Array ("value" => "value2", "name" => "name2", "unique_name" => "unique2"),
    Array ("value" => "value3", "name" => "name3", "unique_name" => "unique3"));

function set_unique_key ($array, $key)
{
    return array_reduce (
        $array,
        function ($res, $elem) use ($key) { 
            $res[$elem[$key]] = array_diff_key ($elem, array ("$key"=>''));
            return $res;
            }, 
        array());
}

print_r (set_unique_key ($input, 'unique_name'));

Answer 5

如果您知道应删除最后一列并使用第一级密钥，则使用

array_pop()

$result = [];
foreach ($input as $row) {
    $result[array_pop($row)] = $row;
}
var_export($result);

如果您正在寻求简洁的代码，那么

extract()

和

compact()

将使事情变得不那么冗长，更 D.R.Y.

$result = [];
foreach ($input as $row) {
    extract($row);
    $result[$unique_name] = compact(['value', 'name']);
}
var_export($result);

演示