PHP array function array_unique() removes duplicate values ​​from the array

This time I will bring you php arrayfunction array_unique() to remove duplicate values ​​in the array, php array function array_unique() to remove duplicate values ​​from the array What are the precautions? The following is a practical case, let’s take a look.

array_unique() function removes duplicate values ​​from an array and returns the resulting array.
When the values ​​of several array elements are equal, only the first element is retained, and the other elements are deleted.

array_unique() Definition and Usage
array_unique() function removes duplicate values ​​from an array and returns the resulting array.

When the values ​​of several array elements are equal, only the first element is retained and the other elements are deleted.

The key names in the returned array remain unchanged.

Syntax

array_unique(array)

Parameter Description
array Required. Specifies the input array.

Description
array_unique() first sorts the values ​​as strings, then only retains the first encountered key name for each value, and then ignores all subsequent key name.
This does not mean that the first occurrence of the same value in the unsorted array will be retained.

Tips and Comments
Comments: The returned array will retain the key type of the first array element.

<?php $a=array("a"=>"Cat","b"=>"Dog","c"=>"Cat"); print_r(array_unique($a)); ?>

Output:

Array ( [a] => Cat [b] => Dog )

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