Convert PHP array to collection of unique elements

In PHP, you can convert an array into a collection of unique elements using the array_unique() function, which will remove duplicate elements and return a new array containing unique elements. The array_unique() function accepts an array as a parameter and can optionally specify the sorting method, such as ascending or numerical sorting. The sorting and deduplication order can be customized using the SORT_FLAG parameter.

Convert an array to a collection of unique elements with PHP

Converting an array to a collection of unique elements is very simple in PHP. This article will show you how to do this using the built-in function array_unique().

array_unique() Function

array_unique() The function can remove duplicate elements from an array and return a new array containing unique elements. It accepts the following parameters:

• array: The array to remove duplicates.
• sort_flags: Optional parameter used to specify how to sort the array.

sort_flags The parameter can specify the following values:

• SORT_REGULAR: Default value, sort by standard comparison operators.
• SORT_NUMERIC: Sort by numeric value.
• SORT_STRING: Sort by string value.
• SORT_LOCALE_STRING: Sort by localized string value.
• SORT_ASC: Sort in ascending order.
• SORT_DESC: Sort in descending order.

Practical case

The following is a practical case for removing duplicate elements from an array:

<?php
$array = [1, 2, 3, 4, 5, 1, 2, 3];

$uniqueArray = array_unique($array);

print_r($uniqueArray);
?>

Output result:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

As you can see, the duplicate elements have been removed from the array.

If you want to sort the array and then remove duplicate elements, you can use the array_unique() function with the SORT_FLAG parameter:

<?php
$array = [5, 3, 1, 3, 2, 4, 2, 1];

$uniqueSortedArray = array_unique($array, SORT_NUMERIC | SORT_ASC);

print_r($uniqueSortedArray);
?>

Output result:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

In the above example, we sort the array in ascending order and then remove duplicate elements.

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