How to remove identical values ​​from php array (three methods)

In PHP, array is a very common data type, often used to store a set of related data. However, in practical applications, there may be duplicate values ​​in the array, and these duplicate values ​​will affect our operation and use of the array. Therefore, we need to learn how to remove identical values ​​from an array.

The following are some common methods:

1. Use array_unique() function

array_unique() function is a function in PHP used to remove duplicates from arrays Value function, its syntax is:

array array_unique ( array $array [, int $sort_flags = SORT_STRING ] )

Among them, $array is an array to remove duplicate values, $sort_flags is an optional parameter, which specifies the way to sort the array, which can be SORT_STRING, SORT_NATURAL , SORT_FLAG_CASE and so on.

The following is an example of using the array_unique() function to remove identical values:

$fruits = array('apple', 'banana', 'orange', 'apple', 'banana');

$unique_fruits = array_unique($fruits);

print_r($unique_fruits);

The output result is:

Array ( [0] => apple [1] => banana [2] => orange )

2. Using the array_diff() function

array_diff() function is a function in PHP used to compare multiple arrays and return the difference set. Its syntax is:

array array_diff ( array $array1 , array $array2 [, array $ ... ] )

Among them, $array1 is the array to be compared, $ array2 is the array to be excluded, $... is an optional parameter, which can contain more arrays to be excluded.

The following is an example of using the array_diff() function to remove identical values:

$fruits = array('apple', 'banana', 'orange', 'apple', 'banana');

$unique_fruits = array_diff($fruits, array('apple'));

print_r($unique_fruits);

The output result is:

Array ( [1] => banana [2] => orange [4] => banana )

3. Use foreach loop

In PHP, we can also use foreach to loop through the array, and then compare the values ​​in the array one by one. If the same value is found, one of them can be deleted.

The following is an example of using a foreach loop to remove the same value:

$fruits = array('apple', 'banana', 'orange', 'apple', 'banana');

foreach ($fruits as $key => $value) {
    if (array_search($value, $fruits) !== $key) {
        unset($fruits[$key]);
    }
}

print_r($fruits);

The output result is:

Array ( [0] => apple [1] => banana [2] => orange )

The above are some common methods that can help us remove them in PHP the same value in the array. Depending on the specific application scenario, we can choose different methods to process the same values ​​in the array to achieve the best operating results.

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