What is the best PHP function to compare two arrays and remove duplicate entries?

When comparing two arrays and removing duplicate entries, the best PHP function to use is `array_diff()`. This function compares two arrays and returns the values from the first array that are not present in any of the other arrays. By using `array_diff()` with the two arrays as arguments, we can easily remove duplicate entries from the first array.

// Define two arrays with duplicate entries
$array1 = [1, 2, 3, 4, 5];
$array2 = [3, 4, 5, 6, 7];

// Remove duplicate entries from $array1
$uniqueArray = array_diff($array1, $array2);

// Output the unique array
print_r($uniqueArray);