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PHP: remove element from multidimensional array (by key) using foreach

I got a multidimensional array. From each subarray, I would like to delete / remove values ​​by index 1. My data is $ array.

Array
(
    [3463] => Array
        (
            [0] => 1
            [1] => 2014
            [context] => 'aaa'
        )

    [3563] => Array
        (
            [0] => 12
            [1] => 2014
            [context] => 'aaa'
        )       

    [2421] => Array
        (
            [0] => 5
            [1] => 2014
            [context] => 'zzz'
        )               
)

I would like to remove each item at index '1' from the subarrays. Desired output:

Array
(
    [3463] => Array
        (
            [0] => 1
            [context] => 'aaa'
        )

    [3563] => Array
        (
            [0] => 12
            [context] => 'aaa'
        )       

    [2421] => Array
        (
            [0] => 5
            [context] => 'zzz'
        )               
)

Why doesn't it work?

foreach ($data as $subArr) {
   foreach ($subArr as $key => $value) {
       if ($key == '1') {
        unset($subArr[$key]);
       }

   }
}

I am sorry if this problem is trivial for you guys.

+3


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4 answers


easy way !? you can only do it with one foreach!



foreach ($data as $key => $subArr) {
    unset($subArr['1']);
    $data[$key] = $subArr;  
}
+7


source


you are making changes to subarray instead of main one, try this, might help



foreach ($data as $key => $subArr) { 
    unset($data[$key][1]);      
}
+4


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try this:

<?php 
    $data = Array
    (
        '3463' => Array
            (
                '0' => 1,
                '1' => 2014,
                'context' => 'aaa'
            ),

        '3563' => Array
            (
                '0' => 12,
                '1' => 2014,
                'context' => 'aaa'
            ),       

        '2421' => Array
            (
                '0' => 5,
                '1' => 2014,
                'context' => 'zzz'
            )               
    );

    foreach ($data as $k=>$subArr) {
        foreach ($subArr as $key => $value) {

            if ($key == '1') {
                unset($data[$k][$key]);
            }

        }
    }
print_r($data);// display the output
+3


source


This does not work, because the $subArr

outer foreach

contains copies of the values $data

, while the inner foreach

changes these copies, leaving $data

them untouched.

You can fix this by instructing PHP

to make $subArr

references to the original values ​​stored in $data

:

foreach ($data as &$subArr) {
   foreach ($subArr as $key => $value) {
       if ($key == '1') {
        unset($subArr[$key]);
       }
   }
}

Another option is to use a function array_map()

. It uses a callback function that can check (and change) each value $data

and returns a new array.

$clean = array_map(
    function (array $elem) {
        unset($elem['1']);        // modify $elem
        return $elem;             // and return it to be put into the result
    },
    $data
);

print_r($clean);
+3


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