Analysis on new Array functions in PHP4

The array Function of php4 has three new members;
Array_unique (), array_intersect (), and array_diff ().

As the name suggests, these three functions are simple:

1. array_unique (array) ------- removes repeated elements from the array and returns the array
Eg:
$ Arr = array ("a", "B", "c", "B ");
$ Arr = array_unique ($ arr );
Var_dump ($ arr); ---- show $ arr only contains three elements: "a", "B", "c"

2. array_intersect (array array1, array, array2...) ---- returns the elements of multiple arrays in the form of arrays.
Eg:
$ Arr1 = array ("a", "B", "c", "d ");
$ Arr2 = array ("e", "f", "B", "");
$ Arr = array_unique ($ arr );
Var_dump ($ arr); ---- display $ arr contains two elements: "a", "B"

3. array_diff (array array1, array array2) ----- returns the elements that array1 does not have compared to array2.
Eg:
$ Arr1 = array ("a", "B", "c", "d ");
$ Arr2 = array ("e", "f", "B", "");
$ Arr = array_unique ($ arr );
Var_dump ($ arr); ---- show $ arr contains two elements: "c" and "d". I think php4 is more user-friendly.