array_reverse

(PHP 4, PHP 5, PHP 7)

array_reverse — 返回单元顺序相反的数组

说明

array_reverse ( array $array [, bool $preserve_keys = FALSE ] ) : array

array_reverse() 接受数组 array 作为输入并返回一个单元为相反顺序的新数组。

参数

array

输入的数组。

preserve_keys

如果设置为 TRUE 会保留数字的键。 非数字的键则不受这个设置的影响，总是会被保留。

返回值

返回反转后的数组。

范例

Example #1 array_reverse() 例子

<?php
$input  = array("php", 4.0, array("green", "red"));
$reversed = array_reverse($input);
$preserved = array_reverse($input, true);

print_r($input);
print_r($reversed);
print_r($preserved);
?>

以上例程会输出：

Array
(
    [0] => php
    [1] => 4
    [2] => Array
        (
            [0] => green
            [1] => red
        )

)
Array
(
    [0] => Array
        (
            [0] => green
            [1] => red
        )

    [1] => 4
    [2] => php
)
Array
(
    [2] => Array
        (
            [0] => green
            [1] => red
        )

    [1] => 4
    [0] => php
)

参见

User Contributed Notes

atulmvAThotmailDOTcoDOTuk 29-Aug-2012 11:48
Here are a couple of routines to swap the order of two elements in an array

<?php

function array_swap_forward($arr,$elem)
{
$ndx = array_search($elem,$arr) - 1;
$b4 = array_slice($arr,0,$ndx);
$mid = array_reverse(array_slice($arr,$ndx,2));
$after = array_slice($arr,$ndx + 2);

return array_merge($b4,$mid,$after);
}

function array_swap_back($arr,$elem)
{
$ndx = array_search($elem,$arr);
$b4 = array_slice($arr,0,$ndx);
$mid = array_reverse(array_slice($arr,$ndx,2));
$after = array_slice($arr,$ndx + 2);

return array_merge($b4,$mid,$after);
}

$arr =array('a','b','c','d','e','f');
print_r(array_swap_forward($arr,'c'));
echo '<br>';
print_r(array_swap_back($arr,'c'));
?>
alfbennett at gmail dot com 06-Apr-2010 01:41
Needed to just reverse keys. Don't flog me if there is a better way. This was a simple solution.

<?php
function array_reverse_keys($ar){
    return array_reverse(array_reverse($ar,true),false);
}
?>
rahulavhad at yahoo dot com 29-Dec-2000 08:31
This code can help in recursive reversing of the array...

<?php
$arr1 = array(2,1,array(5,2,1,array(9,8,7)),5,0);
$arr1 = array_reverse($arr1);

function Reverse_Array($array)
{    $index = 0;
    foreach ($array as $subarray)
    {    if (is_array($subarray))
        {    $subarray = array_reverse($subarray);
            $arr = Reverse_Array($subarray);
            $array[$index] = $arr;
        }
        else {$array[$index] = $subarray;}
        $index++;
    }
    return $array;
}

$arr2 = Reverse_Array($arr1);
?>