Specify the basis for removing duplicate elements when deduplicating PHP arrays

PHP’s array_unique() function is used to remove duplicate elements from an array, and its default use is strict equality (===). We can specify the basis for deduplication through a custom comparison function: create a custom comparison function and specify the deduplication standard (for example, based on element length); pass the custom comparison function as the third parameter to the array_unique() function. Remove duplicate elements based on specified criteria.

Use the PHP array_unique() function to specify the basis for deduplication

Introduction

_unique()Function is used to remove duplicate elements from an array. By default, it uses strict equality (===) to determine duplicate elements. However, we can remove duplicate elements based on different criteria by providing a custom comparison function to specify the basis for deduplication.

Code example

Output result

Array ( [0] => a [1] => b [2] => c [3] => d [4] => e [5] => f ) Array ( [0] => a [1] => b [2] => c [4] => d [6] => e )

Actual case

Suppose we have an array of student objects, each object has a name and age. We can use the_unique()function and a custom comparator to remove students with the same age:

age == $b->age; }; // 使用自定比较器去除重复元素 $unique_students = array_unique($students, SORT_REGULAR, $age_comparator); // 打印唯一学生的姓名 foreach ($unique_students as $student) { echo $student->name . '
'; } ?>

Output result

Alice Carol

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