2d multidimensional array to 1d array in php

Question

Just wondering if anyone has transformed a 2 dim array to a one dim array in php. I\'ve yet to come across a clear explanation in php. Any suggestion would be appreciated.

Answer 1

Your first thought should be array_reduce() whenever you have lots of something in an array and you just want one something by itself which represents them all in some way.

From the PHP docs:

array_reduce — Iteratively reduce the array to a single value using a callback function

In the case of 2D => 1D array conversion, the something is array; we have lots of them in an array but we just want one of them by itself.

function array2dTo1d($array2d)
{
    return array_reduce($array2d, function($carry, $array) {
        return array_merge($carry, $array);
    }, []);
}

var_dump(array2dTo1d(
    [
        [23423, 5454, 567],
        [4565, 687],
    ]
));

Result:

array(5) {
  [0] =>
  int(23423)
  [1] =>
  int(5454)
  [2] =>
  int(567)
  [3] =>
  int(4565)
  [4] =>
  int(687)
}