Comprehensive Guide to PHP's array_uintersect() Function

In this article, we will provide a comprehensive guide to the array_uintersect() function in PHP. This function is used to compare the values of two or more arrays and returns the unique values that are present in all the arrays.

Understanding array_uintersect()

The array_uintersect() function is a built-in PHP function that takes two or more arrays as arguments and returns an array containing the values that are present in all the input arrays.

The syntax for this function is as follows:

array_uintersect(array $array1, array $array2 [, array $..., callable $value_compare_func] ) : array

In this syntax, $array1 is the first array that you want to compare, $array2 is the second array, and $... refers to any additional arrays that you may want to include in the comparison. The final argument, $value_compare_func, is a callback function that defines how the values in the arrays should be compared.

Using array_uintersect() in Practice

To use the array_uintersect() function, you need to understand how the callback function works. This function takes two arguments, which represent the values that are being compared. The function should return a value less than, equal to, or greater than 0, depending on whether the first argument is considered less than, equal to, or greater than the second argument.

For example, here's a simple callback function that compares two strings:

function compare_strings($string1, $string2) {
    return strcmp($string1, $string2);

In this case, the strcmp() function is used to compare the two strings, and the result is returned to the calling function.

Once you have your callback function in place, you can use the array_uintersect() function to compare the arrays. Here's an example:


function compare_strings($string1, $string2) {
    return strcmp($string1, $string2);

$array1 = array("apple", "orange", "banana");
$array2 = array("orange", "banana", "kiwi");
$array3 = array("banana", "kiwi", "grape");

$result = array_uintersect($array1, $array2, $array3, "compare_strings");



In this example, we have three arrays that we want to compare. The compare_strings() function is used to compare the values in the arrays, and the result is stored in the $result variable. Finally, the print_r() function is used to display the result.

Benefits of array_uintersect()

The array_uintersect() function provides several benefits for PHP developers, including:

  1. The ability to quickly and easily compare multiple arrays
  2. The identification of unique values that are present in all the input arrays
  3. The ability to customize the comparison function to fit your specific needs


In conclusion, array_uintersect() is an essential function for PHP developers who need to compare arrays and identify their unique values. By understanding how this function works and using it effectively in your code, you can save time and streamline your development process. So why not give it a try and see how it can benefit your PHP projects?

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