What are the characteristics of the array_diff function in PHP?

The array_diff function in PHP is used to compare the differences between arrays and has the following characteristics:

1. Accept two or more arrays as parameters and return the difference between the first array and the other arrays.
2. The difference array returned contains elements that occur in the first array but not in the other arrays.
3. Sort the elements in the second array in the order of the first array.
4. If multiple different array elements have the same key value, only the first occurrence of the element will be retained, and the subsequent elements will be ignored.
5. The comparison of differences is based on values rather than key-value pairs.
6. For multi-dimensional arrays, only the elements of the first dimension will be compared, and the elements within the subarrays will not be recursively compared.

In summary, the array_diff function is primarily used to compare differences between arrays, returning elements that exist in the first array but not in the other arrays, while preserving the original order of the array.