Welcome to my blog series, PHP Woes! I am pretty sure I’m the one-millionth person complain about PHP, but I have thoughts on features that are used and how they can be used poorly.

So as a non-unique post, my complaint is the lack of understanding of array_combine().

1. The arrays being combined must be the same size: Okay, fair enough. But here’s what happens when you try to combine two arrays of different sizes:

<?php
$a = array('orange','banana');
$b = array('1');
$c = array_combine($a,$b);

Output: PHP Warning: array_combine(): Both parameters should have an equal number of elements in php shell code on line ...

1. There’s no problem with one dimensional arrays with repeated elements. But look what happens when you use array_combine()

// Continue from previous php tag ...
array_push($a,'orange');
array_push($b,'2'); 
array_push($b,'3');
print_r($a);

Output

Array
(
  [0] => orange
  [1] => banana
  [2] => orange
)

// Continue from previous php tag ...
$c = array_combine($a,$b);
print_r($c);

Output

Array
(
  [orange] => 3
  [banana] => 2
)

Basically the element that came in later in the array overwrites the old value.