Add values to an array inside a foreach loop

Question

I'm trying to edit an array on the fly, inside a foreach loop. I basically analyse each key, and if this key match the one I want, I want to add another entry in the array immediately after this one.

If I take this code,

$values = array(
    'foo' => 10,
    'bar' => 20,
    'baz' => 30
);

foreach($values as $key => $value){
    print $value . ' ';
    if($key == 'bar'){
        $values['qux'] = 21;
    }
}

I've got 2 problems,

• first, the output is 10 20 30 instead of the expected 10 20 30 21
• second, even if I solve the first problem, my value will still be added at the end of my array

How could I add the qux entry between bar and baz ones?

Thanks for your ideas.

Answer 1

Foreach will not loop through new values added to the array while inside the loop.

If you want to add the new value between two existing values, you could use a second array:

$values = array(
    'foo' => 10,
    'bar' => 20,
    'baz' => 30
);
$newValues = array();
foreach($values as $key => $value) 
{
    $newValues[$key] = $value;
    if($key == 'bar') 
    {
        $newValues['qux'] = 21;
    }
}
print implode(' ', $newValue);

Also, see one of my favorite questions on StackOverflow discussing the foreach loop: How does PHP 'foreach' actually work?

Answer 2

You can use the ampersand sign before the value.

//populate all the promos into their promoG groups
foreach($unclaimedPromoGroups as &$unclaimedPromoGroup) {
    $_promo = new Promo();
    $_promo->promoGroupID = $unclaimedPromoGroup['promo_groupID'];
    $promo = $_promo->getGroupPromos();
    $unclaimedPromoGroup["promos"] = $promo;
}

Answer 3

For this you need to create a new array,

<?php
$values = array(
    'foo' => 10,
    'bar' => 20,
    'baz' => 30
);

$newarray = array();
foreach($values as $k => $v) 
{
    $newarray[$k] = $v;
    if($k == 'bar') 
        $newarray['qux'] = 21;
}

echo implode(' ', $newarray);

Demo:
http://3v4l.org/N4XgB