PHP array_merge with numerical keys

Question

How can make it so array_merge() overwrites two keys with different values but same key index from two arrays?

for example, merging:

[0] => 'whatever'

with

[0] => 'whatever', [1] => 'a', [2] => 'b'

should produce

[0] => 'whatever', [1] => 'a', [2] => 'b'

Basically I want array_merge to bahave the same way it behaves if the arrays have string keys...

Answer 1

Use the + operator.

Compare array_merge to + operator:

<?php  $a1 = array(0=>"whatever",); $a2 = array(0=>"whatever",1=>"a",2=>"b");  print_r(array_merge($a1,$a2)); print_r($a1+$a2); ?> 

Output:

Array (     [0] => whatever     [1] => whatever     [2] => a     [3] => b ) Array (     [0] => whatever     [1] => a     [2] => b ) 

The + operator still works if your associative array has the numerical keys out-of-order:

<?php  $a1 = array(0=>"whatever",); $a2 = array(1=>"a",0=>"whatever",2=>"b");  print_r(array_merge($a1,$a2)); print_r($a1+$a2); ?> 

Output:

Array (     [0] => whatever     [1] => a     [2] => whatever     [3] => b ) Array (     [0] => whatever     [1] => a     [2] => b ) 

Notice array_merge in this case creates a new key. Not desirable...

Answer 2

array_replace does exactly this!