isNullOrEmpty

Description:

public static bool isNullOrEmpty (string? str)

Check whether string is null or empty.

Example:

    assert (Strings.isNullOrEmpty (null) == true);
    assert (Strings.isNullOrEmpty ("") == true);
    assert (Strings.isNullOrEmpty ("hello") == false);

Parameters:

str	string for checking.

Returns:

true if string is null or empty, false otherwise.