array_diff() on arrays of arrays return wrong results

Asked May 21 '19 at 16:49

Active May 21 '19 at 16:49

Viewed 29 times

My understanding of array_diff(), is that the following code must return array($a[1]).

This is not the behavior. Instead, an array() returned.

What I understand wrong?

<?php
$a = array(
    array('contract' => '5/1-4-2019'),
    array('contract' => '1/1-4-2019'));
$b = array($a[0]);
var_dump(array_diff($a, $b));
?>

asked May 21 '19 at 16:49

Chameleon

array_diff() returns a new array, you're not catching the return value anywhere – jtylerm May 21 '19 at 16:51
1

(PHP Version permitting) you can try `var_dump(array_udiff($a, $b, function($a, $b) { return $a['contract'] <=> $b['contract'];}));` – Nigel Ren May 21 '19 at 16:55
Console catching it via var_dump() – Chameleon May 21 '19 at 16:55
@Nigel Ren My arrays, in sample, are simplified. The question is why `array_diff()` evaluates `$a[1]===$b[0]` as `true` – Chameleon May 21 '19 at 17:01
1

The problem is that it `array_diff` doesn't work with multidimensional arrays properly. – Nigel Ren May 21 '19 at 17:03
Based on @NigelRen answer `var_dump(array_udiff($a, $b, function($a, $b) { return $a <=> $b; }));` – Chameleon May 21 '19 at 17:20

0 Answers0