PHP merging arrays uniquely

Question

So i'm working on a small php applications that combines four arrays. Now there is a possibility that some of the possible arrays will be null. I tried the following solution to merge the four arrays uniquely.

<?php
$a = [1,2,3,4,5];
$b = null;
$c = [5,4,3,2,1];
$d = [1,2];

$new_array;

if(is_array($a) && is_array($b) && is_array($c) && is_array($d))
{
    $new_array =  array_unique(array_merge($a,$b,$c,$d));
}else if(is_array($a) && is_array($b) && is_array($c))
{
        $new_array =  array_unique(array_merge($a,$b,$c));
}else if(is_array($a) && is_array($b))
{   
    $new_array =  array_unique(array_merge($a,$b));
}else{
    $new_array = $a;
}

print_r($new_array);
?>

I soon realized my code was highly dysfunctional in that it does not cater for all possible combinations of arrays while excluding the null variables.

How do I solve this. Ensuring that all the variables that are arrays are merged a nd those that are not are discarded. Thanks

stackoverflow.com/questions/4660675/…

Vaibs_Cool
– Vaibs_Cool

2013-09-30 07:29:26 +00:00
Commented Sep 30, 2013 at 7:29 — Vaibs_Cool
– Vaibs_Cool, Commented Sep 30, 2013 at 7:29

aleation · Accepted Answer · 2013-09-30 07:36:31Z

5

how about this? putting all the array's in an array, so you can loop through them all easily, and use a custom in_array() function to check if they are already existing?

The good thing about this way is that it doesn't limit the script to just four array's, as it will loop through all the array's you get together.

$a = [1,2,3,4,5];
$b = null;
$c = [5,4,3,2,1];
$d = [1,2];

$array_stack = array($a, $b, $c, $d);

$new_array = array();

foreach($array_stack as $stack){
    if(!is_array($stack)) continue;
    foreach($stack as $value){
        if(!in_array($value, $new_array)) $new_array[] = $value;
    }
}

print_r($new_array);

answered Sep 30, 2013 at 7:36

aleation

4,8341 gold badge23 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

elune · Accepted Answer · 2013-09-30 07:32:20Z

3

maybe something like this :

<?php

$a = [1,2,3,4,5];
$b = null;
$c = [5,4,3,2,1];
$d = [1,2];

$new_array;

if(is_array($a)) $new_array = $a;
if(is_array($b)) $new_array =  array_unique(array_merge($new_array,$b));
if(is_array($c)) $new_array =  array_unique(array_merge($new_array,$c));
if(is_array($d)) $new_array =  array_unique(array_merge($new_array,$d));
?>

answered Sep 30, 2013 at 7:32

elune

3381 silver badge9 bronze badges

Comments

Matthias Van Parijs · Accepted Answer · 2015-09-25 15:09:30Z

0

Old question, but going to give my input anyways. A more universal approach:

function multiple_array_merge() {
    $args = func_get_args();

    $array = [];
    foreach ($args as $i) {
        if (is_array($i)) $array = array_merge($array, $i);
    }

    return array_unique($array);
}

$a = [1, 2, 3, 4, 5];
$b = null;
$c = [5, 4, 3, 2, 1];
$d = [1, 2];

$merged = multiple_array_merge($a, $b, $c, $d);

answered Sep 25, 2015 at 15:09

Matthias Van Parijs

2712 silver badges8 bronze badges

Collectives™ on Stack Overflow

PHP merging arrays uniquely

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related