乘以 2 数组多维并删除键

Question

我有一个包含一些数字的多维数组，我想将包含键 0 的 数组的值与一个区域数组中的其他键相乘并擦除 key 0.

数组

Array
(
    [0] => Array
        (
            [0] => 3
            [1] => 5
            [2] => 5
            [3] => 6
            [4] => 7
        )

    [1] => Array
        (
            [0] => 2
            [1] => 7
            [2] => 4
            [3] => 2
            [4] => 8
        )

    [2] => Array
        (
            [0] => 4
            [1] => 2
            [2] => 3
            [3] => 2
            [4] => 5
        )
)

这是我想要的结果

Array
(
    [0] => Array
        (
            [0] => 15
            [1] => 15
            [2] => 18
            [3] => 21
        )

    [1] => Array
        (
            [0] => 14
            [1] => 8
            [2] => 4
            [3] => 16
        )

    [2] => Array
        (
            [0] => 8
            [1] => 12
            [2] => 8
            [3] => 20
        )
)

我已经使用 foreach 和 for 组合了它，但它仍然不适合我，知道怎么做吗？

Answer 1

使用array_map和array_slice函数的解决方案：

// $arr is your initial array
foreach ($arr as &$v) {
    $multiplier = $v[0];
    $v = array_map(function($val) use($multiplier){
        return  $multiplier * $val;        
    }, array_slice($v, 1));
}

print_r($arr);

输出：

Array
(
    [0] => Array
        (
            [0] => 15
            [1] => 15
            [2] => 18
            [3] => 21
        )

    [1] => Array
        (
            [0] => 14
            [1] => 8
            [2] => 4
            [3] => 16
        )

    [2] => Array
        (
            [0] => 8
            [1] => 12
            [2] => 8
            [3] => 20
        )
)