Algorithm (4th edition) -1.2.3 implementation of abstract data types

Summary: This section details the implementation of abstract data types, including instance variables, constructors, creation of instance methods, scope of three variables and APIs, use cases and implementations.

Focus:

1. If the instance variable should not be changed after initialization, we will use final.

2. If no constructor is defined, the class implicitly defines a constructor that does not accept any arguments by default and initializes all instance variables to their default values.

3. There is a key difference between instance methods and static methods: instance methods can access and manipulate instance variables.

4. Scope of three variables:

· Parametric variables: the whole method;

· Local variable: All statements after its definition in the current code snippet;

· Instance variable: the entire class.

5. If the instance variable has two semantics, you can use the this prefix to differentiate the instance variable.

 Public classExample {Private intvar; ...    Private voidmethod1 () {intvar//Local Variables. .. var//a local variable is called, not an instance variable... This. var//Invoking instance Variables    }    Private voidmethod2 () {... var//Invoking instance Variables    }    ...}

6. The role of the API is to separate the use and implementation.

Algorithm (4th edition) -1.2.3 implementation of abstract data types