Merge array values, alternating

Question

I'm trying to merge arrays but would like to alternate the order.

$combined = array_merge($vars,$mods);

gives me: one,two,three,1,2,3...

I'd like: one,1,two,2,three,3...

is there a way to do this?

What if the arrays have different numbers of items? Just push all the extra ones from the larger array onto the end of the result? — Don't Panic, Oct 06 '16 at 15:17
In my form both form the fields are set up so that for every entry in the $vars array there is an equivalent entry in the $mods array. Both will always have an equal number of values. — Jamie Moffat, Oct 06 '16 at 15:21
What is your array in the first place? Please provide more context. — Sainan, Oct 06 '16 at 16:05

Don't Panic · Accepted Answer · 2016-10-06T15:57:55.820

3

You can use a for loop and refer to the index of each of the arrays you're combining.

$l = count($vars);
for ($i=0; $i < $l; $i++) {
    $combined[] = $vars[$i];
    $combined[] = $mods[$i];
}

In each iteration of the loop, you'll append one item from each of the original arrays. This will achieve the alternating effect.

As Steve pointed out, this can be done more simply using foreach:

foreach ($vars as $i => $value) {
    $combined[] = $value;
    $combined[] = $mods[$i];
}

edited Oct 06 '16 at 15:57

answered Oct 06 '16 at 15:23

Don't Panic

I'd suggest building it as a function so you can use it in multiple places if needed. – Allen Butler Oct 06 '16 at 15:24
If the keys are always sequential in both arrays you can replace the first two lines with `foreach($vars as $i => $value) {` – Steve Oct 06 '16 at 15:54

1 Answers1