I have two arrays $a and $b
$a = [
'0' => [
'name'=>'Apple',
'id' => 1
],
'1' => [
'name'=>'Banana',
'id' => 2
],
'2' => [
'name' => 'orange',
'id' => 3
]
];
AND
$b = [
'0' => [
'price'=> 20,
'a_id' => 2
],
'1' => [
'price'=> 10,
'a_id' => 3
],
'3' => [
'price'=> 30,
'a_id' => 1
]
];
I am trying to create another array with mapping with id(array $a), a_id (array $b), where my output will looks like:
$a = [
'0' => [
'id' => 1
'name'=>'Apple',
'price' => 30
],
'1' => [
'id' => 2
'name'=>'Banana',
'price' => 20
],
'2' => [
'id' => 3
'name' => 'orange',
'price' => 10
]
];
I have tried by array map
$combined = array_map(null,$a,$b);
But this result is not my desire result. How can I map my 1st array with 2nd array related by $a['id'] = $b['a_id']?
This should work, also if there's no price for an item in the array $b then the default price 0 will be added.
<?php
$result = [];
$t = array_column($b, 'a_id');
foreach($a as $k => $v) {
$index = array_search($v['id'], $t);
$v['price'] = $index !== FALSE ? $b[$index]['price'] : 0;
$result[] = $v;
}
print_r($result);
?>
Result:
(
[0] => Array
(
[name] => Apple
[id] => 1
[price] => 30
)
[1] => Array
(
[name] => Banana
[id] => 2
[price] => 20
)
[2] => Array
(
[name] => orange
[id] => 3
[price] => 10
)
)
You can do it as follows:
foreach($a as $k => $item)
{
$price = 0;
foreach($b as $priceItem)
{
if($priceItem['a_id'] === $item['id'])
{
$price = $priceItem['price'];
break;
}
}
$a[$k]['price'] = $price;
}
However, this isn't too efficient as every new price and item will exponentially increase the loops required.
If you are able to use the product IDs as the key in your first array, you could do it a lot more efficiently:
// Key $a by product ID
$a = [
1 => [
'name'=>'Apple',
'id' => 1
],
2 => [
'name'=>'Banana',
'id' => 2
],
3 => [
'name' => 'orange',
'id' => 3
]
];
foreach($b as $priceItem)
{
$a[$priceItem['a_id']]['price'] = $priceItem['price'];
}
You can use this code
$result = [];
for($i=0; $i<sizeof($a); $i++){
if(array_key_exists($i,$b)){
$b[$i]['id']=$b[$i]['a_id'];
unset($b[$i]['a_id']);
}
$result[] = array_merge($a[$i], array_key_exists($i,$b)?$b[$i]:array());
}
print_r($result);