Do Array Keys Have To Be Unique ?

Folks,

Why can’t array keys be duplicates while values unique ? Duplicate keys for grouping purpose.
Based on following test, keys must be unique
Test this code on your ends.

[code]
<?php

$array_duplicates_1 = array(‘personal’ => ’email’,’commercial’ => ’email’);
$array_duplicates_2 = array(‘personal’ => ’email’,’personal’ => ‘domain’);
$array_duplicates_3 = array(‘personal’ =>’email’,’commercial’ =>’domain’);

print_r($array_duplicates_1);
echo ‘<br>’;
print_r($array_duplicates_2);
echo ‘<br>’;
print_r($array_duplicates_3);
echo ‘<br>’;

$array_non_duplicates_1 = array_unique($array_duplicates_1);
$array_non_duplicates_2 = array_unique($array_duplicates_2);
$array_non_duplicates_3 = array_unique($array_duplicates_3);

print_r($array_non_duplicates_1);
echo ‘<br>’;
print_r($array_non_duplicates_2);
echo ‘<br>’;
print_r($array_non_duplicates_3);
echo ‘<br>’;

?>
[/code]

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