Php 用编号键替换命名键

在多维数组中，用编号键替换命名键的最有效、最简洁的方法是什么

我的阵列：

Array 
(
    [0] => Array 
        (
            [Property] => Brock
            [Meint. Type] => grounds
            [Maint. Task] => plow snow
            [Status] => cancelled
            [Started] =>
            [Completed] =>
            [Comments] =>
        )

    [1] => Array 
        (
            [Property] => Brock
            [Meint. Type] => grounds
            [Maint. Task] => plow snow
            [Status] => pending
            [Started] => 2010-01-16
            [Completed] =>
            [Comments] =>
        )

    [2] => Array
        ( 
            [Property] => Brock
            [Mains. Type] => grounds
            [Maint. Task] => plow snow
            [Status] => complete
            [Started] => 2010-01-16
            [Completed] => 2010-01-16
            [Comments] =>
        )

    [3] => Array 
        (
            [Property] => Brock
            [Mains. Type] => grounds
            [Maint. Task] => plow snow
            [Status] => in progress
            [Started] => 2014-01-16
            [Completed] => 2014-01-16
            [Comments] =>
        )

    [4] => Array

目标是将[Property]替换为[0]，[Maint.Type]替换为[1]（应该用方括号括起来，它们将被自动删除），[Maint.Task]替换为[2]，[Status]替换为[3]等等，用于每个子数组

$modified_array = array_map('array_values', $arr);

说明：将函数应用于

$arr

数组中的每个元素