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There are three common methods for deduplicating arrays in php: 1. The "array_unique()" function can remove duplicate values in the array and return a new array; 2. Use a loop to delete duplicates, use for Or a foreach loop traverses the entire array to determine whether there are duplicates and delete them; 3. Use the "array_flip()" and "array_keys()" functions. The "array_flip()" function exchanges the keys and values of the array, and "array_keys()" Get all key names.
Operating system for this tutorial: Windows 10 system, php8.1.3 version, Dell G3 computer.
There are three common ways to remove duplicates from arrays in php:
1. Use the array_unique() function
array_unique() function to remove duplicates from the array of repeated values and returns a new array.
$array = array("a" => "apple", "b" => "banana", "c" => "apple"); $unique_array = array_unique($array); print_r($unique_array);
The output result is:
Array ( [a] => apple [b] => banana )
2. Use a loop to delete duplicate items
Use a for or foreach loop to traverse the entire array and judge Check if there are duplicates and delete them. This method works well for small arrays, but can be time-consuming for large arrays.
$array = array("a" => "apple", "b" => "banana", "c" => "apple"); foreach ($array as $key => $value) { $count = 0; foreach ($array as $k => $v) { if ($v == $value) { $count++; if ($count > 1) { unset($array[$k]); } } } } print_r($array);
Output:
Array ( [a] => apple [b] => banana )
3. Use the array_flip() and array_keys() functions
Use the array_flip() function to convert the keys and values of the array Swap, and use array_keys() to get all key names. Since the keys are unique, this effectively creates a set of results that does not contain duplicate items.
$array = array("a" => "apple", "b" => "banana", "c" => "apple"); $unique_array = array_flip(array_flip($array)); print_r($unique_array);
The output is:
Array ( [a] => apple [b] => banana )
These methods are only a few methods that can achieve array deduplication. There are other methods such as using array_count_values(), array_reduce(), etc. For developers to master according to actual needs.
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