How to merge two arrays with duplicate keys - php

Question

I have two arrays $rate_row and $totalrowcost I am trying to update a row in the second array $totalrowcost based on the key in the first array $rate_row both arrays are always the same length.
I combine both arrays using the array_combine function
my code below works if there are no duplicate keys in the array but if i combine them when there are duplicate keys
I don't get the desired result.
Example:
If the key in $rate_row is 0 I need to set the value in $totalrowcost to 0 but when combining the array, one of the rows gets dropped and only one row with a key of 0 is preserved.
I've since learned since trying to figure this out that PHP will not allow an array to have a duplicate key, but i was wondering if there is some type of work around or hack that can help any ideas would be great thanks.
enter code here
<?php
// Finds the lowest duty rate
$lowest = 0;
$row_combine = array_combine($rate_row, $totalrowcost);
foreach($row_combine as $a => $combine_row):
if ($a = 0){
$lowest = $a;
echo "";
}
endforeach;
// Finds the row value associated with the lowest duty rate
foreach($row_combine as $a => $combine_row):
if ($a === $lowest){
$lowest1 = $combine_row;
}
endforeach;
for($i = 0; $i < count($totalrowcost); $i++) {
enter code here
if ($totalrowcost[$i] == $lowest1){
$totalrowcost[$i] = 0;
}
}?>
enter code here
$rate_row
Array
(
[0] => 35
[1] => 0
[2] => 40
[3] => 0
[4] => 45
)
$totalrowcost
Array (
[0] => 100
[1] => 49.99
[2] => 102
[3] => 98
[4] => 125
)
$row_combine Output
Array (
[35] => 100
[0] => 98
[40] => 102
[45] => 125
)
Desired $row_combine Output
Array (
[35] => 100
[0] => 49.99
[40] => 102
[0] => 98
[45] => 125
)
Actual Output updated
$totalrowcost
Array (
[0] => 100
[1] => 49.99
[2] => 102
[3] => 0
[4] => 125
)
Desired Output updated
$totalrowcost
Array (
[0] => 100
[1] => 0
[2] => 102
[3] => 0
[4] => 125
)

Answer 1

documentation for class to read up on the syntax and more information about them.
I'm a little unclear as to what problem you are trying to solve, perhaps an edit on what the use case is might help suggest other options.
EDIT:
<?php
// you can use whatever input $rate_row is from user input or such along with the $totalrowcost
$rate_row = [35, 0, 40, 0, 45];
$totalrowcost = [100, 49.99, 102, 98, 125];
class Table {
public $row_items;
public $row_rates;
public $row_rate_applied;
private $lowestRate;
// used to init class values
function __construct($items, $rates) {
// set variables to class
// might want to run validation here to make sure the count is = for $items and $rates
$this->row_items = $items;
$this->row_rates = $rates;
$this->lowestRate = min($rates); // add validation to make sure rates is array http://php.net/manual/en/function.min.php
// main guts that are used to solve your problem is inside this loop
for($i = 0; $i < count($items); $i++) {
// here we test if rates index == lowest. if it is set the item value to lowest
if ($rates[$i] == $this->lowestRate) {
$this->row_rate_applied[$i] = $this->lowestRate;
} else {
$this->row_rate_applied[$i] = $items[$i];
}
}
}
}
$table = new Table($totalrowcost, $rate_row);
echo var_dump($table->row_rate_applied);
The above code builds up and applies the rates against the items. I'm not 100% what the expected result is actually supposed to be because the code originally posted doesn't make a ton of sense for the expected output
essentially the idea is to build your Row

Answer 2

If the keys have no significant value (i.e. you just want to later loop over the final array) you can make sure the keys are unique before you merge them by appending a random name at the end of them.
Here is a function that merges two arrays while keeping the duplicate keys.
function array_uniqify_keys($array,$append='',$glue='--'){
if($append === ''){
$append = uniqid() . mt_rand(1000,9999);
}
foreach($array as $key => $value){
unset($array[$key]);
$array[$key.$glue.$append] = $value;
}
return $array;
}
function array_merge_duplicate_safe($array1,$array2,$a1_name='',$a2_name=''){
$array1 = array_uniqify_keys($array1,$a1_name);
$array2 = array_uniqify_keys($array2,$a2_name);
return array_merge($array1,$array2);
}
$array1 = [
1 => 'foo',
2 => 'boo'
];
$array2 = [
1 => 'good',
2 => 'bad',
3 => 'ugly'
];
print_r(array_merge_duplicate_safe($array1,$array2));
The result for the above code is:
Array
(
[1--59d393950489c8380] => foo
[2--59d393950489c8380] => boo
[1--59d39395049197021] => good
[2--59d39395049197021] => bad
[3--59d39395049197021] => ugly
)
You can also get the old key by explode('--',$key)[0].