Merging two arrays removing duplicate keys from one - php

Question

I have two arrays. Those are below:
First Array:
$arr1[0] = 'Programs';
$arr1[1] = 'Levels';
$arr1[2] = 'Presenters';
$arr1[3] = 'Levels';
Second Array:
$arr2[0] = 'Art';
$arr2[1] = 'Primary';
$arr2[2] = 'Kristine Ballard';
$arr2[3] = 'Secondary';
I want to get output like this:
Programs = Art
Levels = Primary, Secondary
Presenters = Kristine Ballard
Can anyone help?

Answer 1

With the following, you would create a multidimensional array, if there are multiple values of a key:
$arr1[0] = 'Programs';
$arr1[1] = 'Levels';
$arr1[2] = 'Presenters';
$arr1[3] = 'Levels';
$arr2[0] = 'Art';
$arr2[1] = 'Primary';
$arr2[2] = 'Kristine Ballard';
$arr2[3] = 'Secondary';
$newArray = array();
foreach($arr1 as $index => $key) {
$newArray[$key][] = $arr2[$index];
}
print_r($newArray);
Output:
Array
(
[Programs] => Array
(
[0] => Art
)
[Levels] => Array
(
[0] => Primary
[1] => Secondary
)
[Presenters] => Array
(
[0] => Kristine Ballard
)
)

Answer 2

$arr1[0] = 'Programs';
$arr1[1] = 'Levels';
$arr1[2] = 'Presenters';
$arr1[3] = 'Levels';
$arr2[0] = 'Art';
$arr2[1] = 'Primary';
$arr2[2] = 'Kristine Ballard';
$arr2[3] = 'Secondary';
$newArray = [];
$mi = new MultipleIterator();
$mi->attachIterator(new ArrayIterator($arr1));
$mi->attachIterator(new ArrayIterator($arr2));
foreach($mi as list($key, $value)) {
$newArray[$key][] = $value;
}
var_dump($newArray);
Note that the use of foreach() with list() requires PHP>=5.5.0
For earlier versions of PHP, the following will work:
$newArray = [];
$mi = new MultipleIterator(MultipleIterator::MIT_NEED_ALL | MultipleIterator::MIT_KEYS_ASSOC);
$mi->attachIterator(new ArrayIterator($arr1), 'key');
$mi->attachIterator(new ArrayIterator($arr2), 'value');
foreach($mi as $details) {
extract($details);
$newArray[$key][] = $value;
}
var_dump($newArray);

Answer 3

I got another solution by myself and this is working. I have just posted it below for the help to others who will see this thread. Here is my code:
$arr1[0] = 'Programs';
$arr1[1] = 'Levels';
$arr1[2] = 'Presenters';
$arr1[3] = 'Levels';
$arr2[0] = 'Art';
$arr2[1] = 'Primary';
$arr2[2] = 'Kristine Ballard';
$arr2[3] = 'Secondary';
$new_arr1 = array_values(array_unique($arr1));
for ($i = 0; $i < count($new_arr1); $i++)
{
$var = 0;
echo $new_arr1[$i]. ': ';
for ($j = 0; $j < count($arr1); $j++)
{
if($new_arr1[$i] == $arr1[$j])
{
if($var == 0)
{
echo $arr2[$j];
}
else
{
echo ', ' . $arr2[$j];
}
$var++;
}
}
echo '<br>';
}