Pramod Sivadas Pramod Sivadas - 2 months ago 11
PHP Question

php array_unique sorting behavior

I am checking the array_unique function. The manual says that it will also sort the values. But I cannot see that it is sorting the values. Please see my sample code.

$input = array("a" => "green", 3=>"red", "b" => "green", 1=>"blue", "red");
print_r($input);
$result = array_unique($input,SORT_STRING);
print_r($result);

The output is

Array
(
[a] => green
[3] => red
[b] => green
[1] => blue
[4] => red
)
Array
(
[a] => green
[3] => red
[1] => blue
)


Here the array $result is not sorted. Any help is appreciated.

Thank you
Pramod

Answer

array_unique:

Takes an input array and returns a new array without duplicate values.

Note that keys are preserved. array_unique() sorts the values treated as string at first, then will keep the first key encountered for every value, and ignore all following keys.

you can try this to get the result:

<?php 
$input = array("a" => "green", 3=>"red", "b" => "green", 1=>"blue", "red");
print_r($input);
$result = array_unique($input);
print_r($result);
asort($result);
print_r($result);
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