To use a predefined method in a program, you need to know the name of the class containing the method (unless the class, such as the class String, is automatically imported) and the name of the package containing the class, and then you need to import the class into the program. In addition, you need to know the name of the method, the number of parameters the method takes, and the type of each parameter. You must also be aware of the method's return type or, loosely speaking, what the method produces.