Question

我有这个多维的输入数组。

$input = array(
    array(11, 12, 13, 14, 15),
    array(21, 22, 23, 24, 25),
    array(31, 32, 33, 34, 35),
    array(41, 42, 43, 44, 45),
    array(51, 52, 53, 54, 55)
);

我想从此数组中的每个实体中减去1，以便结果变为

$output = array(
    array(10, 11, 12, 13, 14),
    array(20, 21, 22, 23, 24),
    array(30, 31, 32, 33, 34),
    array(40, 41, 42, 43, 44),
    array(50, 51, 52, 53, 54)
);

我的解决方案

function sub ($a)
{
    return $a-1;  // what should go here? 
}
$output = array_map("sub", $input);

请帮助!!!

Answer 1

我确信比我聪明的人可以想到使用循环的另一种方法，但如果你不想要array_map()我只能考虑使用另一个foreach()：

<?php
    function subtractor($v)
        {
            $sub    =   1;
            return ((int)$v - (int)$sub);
        }

    function annon($v)
        {
            return array_map("subtractor",$v);  
        }

    $arr    =   array_map("annon", $input);

    print_r($arr);
?>

给你：

Array
(
    [0] => Array
        (
            [0] => 10
            [1] => 11
            [2] => 12
            [3] => 13
            [4] => 14
        )

    [1] => Array
        (
            [0] => 20
            [1] => 21
            [2] => 22
            [3] => 23
            [4] => 24
        )

    [2] => Array
        (
            [0] => 30
            [1] => 31
            [2] => 32
            [3] => 33
            [4] => 34
        )

    [3] => Array
        (
            [0] => 40
            [1] => 41
            [2] => 42
            [3] => 43
            [4] => 44
        )

    [4] => Array
        (
            [0] => 50
            [1] => 51
            [2] => 52
            [3] => 53
            [4] => 54
        )

)

Answer 2

您可以尝试的另一种方式

<!DOCTYPE html>
<html>
<body>

<?php
$cars = array(
    array(11, 12, 13, 14, 15),
    array(21, 22, 23, 24, 25),
    array(31, 32, 33, 34, 35),
    array(41, 42, 43, 44, 45),
    array(51, 52, 53, 54, 55)
);
     
for ($row = 0; $row <  5; $row++) {
   echo "<p><b>Row number $row</b></p>";
   echo "<ul>";
   for ($col = 0; $col <  5; $col++) {
	   $cars[$row][$col] = $cars[$row][$col] - 1;
     echo "<li>".$cars[$row][$col]."</li>";
   }
   echo "</ul>";
}
?>

</body>
</html>

使用http://phpfiddle.org/

运行代码

Answer 3

array_map函数正在使用一个暗淡的数组，你需要执行两次，参见代码

<?php 
$input = array(
    array(11, 12, 13, 14, 15),
    array(21, 22, 23, 24, 25),
    array(31, 32, 33, 34, 35),
    array(41, 42, 43, 44, 45),
    array(51, 52, 53, 54, 55)
);
$op = array_map(function($v){
  return array_map(function($v1){return $v1 - 1;}, $v);
}, $input);
print_r($op);

在PHP中修改多维数组

3 个答案:

DEMO