APIs, documentation, method signatures and class methods

Learning objectives

Explain how a library groups classes into packages and how its API documentation describes them, and identify the attributes (data held in variables) and behaviors (methods) of a class from that documentation

Write the three kinds of Java comment, including Javadoc, and state the precondition and postcondition of a method from its description, knowing that the method is not expected to check its own preconditions

Identify a method signature as the method name plus its ordered parameter types, distinguish a parameter from an argument, and explain that call by value gives each parameter a copy of its argument

Distinguish a void method, whose call stands alone as a statement, from a non-void method whose returned value must be stored or used in an expression, and trace how control passes into a method and back to the caller

Identify overloaded methods and determine which version a call runs from the number, order and types of its arguments

Call a class (static) method by writing the class name, a dot and the method name, and explain how procedural abstraction lets a programmer rely on a method’s documented result without reading its code