PHP Get the first value of all arrays in a multidimensional array

Question

Here's a section my multidimensional array:

Array ( 
[0] => Array ( [0] => Height [1] => 40 ) 
[1] => Array ( [0] => Weight [1] => 15 ) 
[2] => Array ( [0] => Ctr_Percent [1] => 15 ) 
)

What would the syntax be for just printing height, weight, and ctr_percent? I don't mean echoing it like:

echo $array[0][0];
echo $array[1][0];

Is there a way to iterate through the entire multidimensional array and echo out the first value of each child array?

score 22 · Answer 1 · answered Apr 22 '12 at 21:37

22

Supposing you use php 5.3:

$first_elements = array_map(function($i) {
    return $i[0];
}, $data);

Otherwise you need to implement a callback function or just use plain old foreach

answered Apr 22 '12 at 21:37

zerkms

I think it should be noted that that works only if index 0 happens to be the key of the first element in the array. It simply doesn't return the first value of the subarray it just returns the value of the element with key 0 which might be the first element. – Christoph Diegelmann Dec 06 '16 at 15:36
@Christoph the element with the index 0 of a numerically indexed array is semantically "the first value of the subarray". If the nested arrays are not numerically indexed - there is really no much sense to speak about their "order" at all. – zerkms Dec 06 '16 at 19:20
php has an order for each array independant of it's keys e.g. in [1=>5,0=>3] the array in numerically index yet still key 1 is the first element not zero. You will always iterate over this implicit order using foreach not in sorted order of the keys. There are no plain arrays like in c like languages. – Christoph Diegelmann Dec 07 '16 at 09:34

score 17 · Answer 2 · answered Dec 06 '16 at 15:23

17

Here is a one-liner:

array_map('array_shift', $array);

Will return:

Array
(
    [0] => Height
    [1] => Weight
    [2] => Ctr_Percent
)

And here is another one:

array_combine(array_map('array_shift', $temp), array_map('array_pop', $temp))

Will return:

Array
(
    [Height] => 40
    [Weight] => 15
    [Ctr_Percent] => 15
)

answered Dec 06 '16 at 15:23

Shumoapp

score 6 · Answer 3 · answered Jul 24 '20 at 16:14

6

$result = array_column($array, 0);

answered Jul 24 '20 at 16:14

Robo Robok

score 1 · Accepted Answer · edited Oct 19 '14 at 11:56

1

foreach ($main_array as $inner_array){
  echo $inner_array[0] . "\n";
}

edited Oct 19 '14 at 11:56

Lucas Zamboulis

answered Apr 22 '12 at 21:37

John Conde

score 1 · Answer 5 · answered Apr 22 '12 at 21:40

1

foreach($array as $x) {
   echo $x[0]."\n";
}

answered Apr 22 '12 at 21:40

gopi1410

score 1 · Answer 6 · answered Dec 06 '16 at 15:33

I think the function your looking for is reset() e.g.

array_map('reset', $array);

or

foreach ($array as $subarray)
    echo reset($subarray)."\n";

Note that this works even if 0 is not the first index of the array. E.g. $a = [1=>5,0=>3]; echo reset($a); would still echo 5;.

score 1 · Answer 7 · answered Jul 31 '19 at 10:01

The easiest way to do it using array_walk

        function getFirstElement(&$val){
            $val = $val[0];
        }
        array_walk($data,'getFirstElement');

Now if you print $data like print_r($data); you will get result as below

Array
(
   [0] => Height
   [1] => Weight
   [2] => Ctr_Percent
)

7 Answers7