substitute the elements of an array coditionally - php

Question

I need to create an array of prices. So I've an array of base prices and an array of promotional prices, if the promotional price is lower than the base price, I put it in the new array of prices. For this purpose I wrote this code:
<?php
$array_base_prices = array(
array('id'=>1, 'price'=>10),
array('id'=>2, 'price'=>2),
array('id'=>3, 'price'=>30),
array('id'=>4, 'price'=>40)
);
$array_promo = array(
array('id'=>1, 'price'=>20),
array('id'=>2, 'price'=>5),
array('id'=>3, 'price'=>2)
);
$base_prices_with_promo = array();
foreach ( $array_base_prices as $j => $u ) {
foreach ( $array_promo as $k => $v ) {
if ( ($v['id'] == $u['id']) && $u['price'] < $v['price']) {
$base_prices_with_promo[$j]['id'] = $array_base_prices[$j]['id'];
$base_prices_with_promo[$j]['price'] = $array_base_prices[$j]['price'];
}
if ( ($v['id'] == $u['id']) && $u['price'] > $v['price']) {
$base_prices_with_promo[$j]['id'] = $array_promo[$k]['id'];
$base_prices_with_promo[$j]['price'] = $array_promo[$k]['price'];
}
}
}
$base_prices_with_promo = array_replace( $array_base_prices, $base_prices_with_promo );
echo "<pre>";
print_r($base_prices_with_promo);
echo "</pre>";
?>
and it works fine, but I think that the if conditions into the nested foreach are a little messy. I'm working with multidimensional, associative arrays, very big with a lot of keys. So I'm wondering if there is any better alternative to achieve the same result.

Answer 1

There's really not enough context for me to be sure that this is an option for you, but from your little example I would change the array declaration to this:
$array_base_prices = array(
1 => 10,
2 => 2,
3 => 30,
4 => 40
);
$array_promo = array(
1 => 20,
2 => 5,
3 => 2
);
Or use an array if you need to store more data than just price:
$array_base_prices = array(
1 => array("price" => 10, "something_else" => null)
);
The point is to have the id as index of the parent array. Then your nested loops turn to this:
foreach ($array_base_prices as $id => $base_price) {
$base_prices_with_promo[$id] = $base_price;
if (isset($array_promo[$id]) && $base_price > $array_promo[$id]) {
$base_prices_with_promo[$id] = $array_promo[$id];
}
}