Reverse multidimensional array without any sort method in php

Question

I'm studying how to manipulate array in PHP. Now, I have a issue about multidimensional array. I want to reverse 2d array without any sort method.This issue doesn't allow us to use array_reverse.

$numArray = array(1,2,3,array(4,5,6),7);

function numReverse($num) {
$reverseArray=array();
$subValueArr=array();

for($count=count($num), $i=$count-1; $i >= 0; $i--){
$reverseArray[]=$num[$i];
}
foreach($num as $value){
If(is_array($value)){
for($subCount=count($value),$j=$subCount-1; $j--){
$subValueArr[]=$value[$j];
}
}
}
$reverseArray[1][]=$subValueArr;
return $reverseArray;
}

$result=numReverse($numArray);
print_r($result);

I expect this output

array{int(7),array{int(6),int(5),int(4)},int(3),int(2),int(1)}

I want like this. array{int(7),array{int(6),int(5),int(4)},int(3),int(2),int(1)} — Shinya Ota
– Shinya Ota, Commented Oct 14, 2015 at 12:22
Just access reverse.... Suppose if you want to access array dynamically. For eg. if you want to access 30th element. Then in reverse it is at 70th position. then to get position... count(array_size)-(original array position). — Rohan Khude
– Rohan Khude, Commented Oct 14, 2015 at 12:30

Rohit Kumar · Accepted Answer · 2015-10-14 12:39:22Z

2

Just do it as , (if you are rigid to not use array_reverse)

<?php
$numArray = array(1,2,3,array(4,5,6),7);
$result=reverse($numArray);
print_r($result);
function reverse($arr)
{
end($arr);
 do
 {
     if(is_array(current($arr)))
         $result[]=reverse(current($arr));
     else
         $result[]=current($arr);
 }while(prev($arr));
return $result;
}  
?>

OUTPUT

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

edited Oct 14, 2015 at 12:39

answered Oct 14, 2015 at 12:23

Rohit Kumar

1,9581 gold badge12 silver badges17 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

u_mulder · Accepted Answer · 2015-10-14 12:34:35Z

1

Easiest way is to use array_reverse (for your 2d array):

$numArray = array(1,2,3,array(4,5,6),7);
foreach ($numArray as &$ar) {
    if (is_array($ar))
        $ar = array_reverse($ar);
}
$result = array_reverse($numArray);
var_dump($result);

For 3D and more dimesnions arrays you'll require a recursive function.

answered Oct 14, 2015 at 12:34

u_mulder

54.8k5 gold badges54 silver badges72 bronze badges

1 Comment

Whip Over a year ago

Can you explain &$ar in your foreach?

alanmm · Accepted Answer · 2015-10-14 12:34:00Z

0

Using array_walk you'll walk through each array's element passing a custom callback (in this case, checking if they contain an array). If it does, the value receives the result of array_reverse, which gives the array in reverse order (set true after the value if you want to keep the key association)

<?php
$numArray = array(1,2,3,array(4,5,6),7);
array_walk($numArray, function(&$v) {
    return !is_array($v) ? : $v = array_reverse($v);
});

Outputs (before and after array_walk)

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

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

    [4] => 7
)

edited Oct 14, 2015 at 12:34

answered Oct 14, 2015 at 12:32

alanmm

1,7051 gold badge14 silver badges21 bronze badges

1 Comment

u_mulder Over a year ago

And reverse the result)

Collectives™ on Stack Overflow

Reverse multidimensional array without any sort method in php

3 Answers 3

Comments

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related