Week3

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deterministic (for) 确定性的 non-deterministic

• for loops (fixed number of times)

• while loops (not fixed)

• do ... while loops (not fixed)

Array

//两种声明Array的方式
int[] numbers = new int[6];
int numbers[] = new int[6];
//elements all 0
int[] numbers = {2, 3, 5, 0, 1, 4};

• accessing array

for (int i = 0; i < numbers.length; i++) {
    System.out.println("numbers[" + "i" + "]:" + numbers[i]);
}

Principle of OOP

Objects contain both data and the functionality that operates on that data. Controlled by:

• Encapsulation 封装

• Inheritance 继承

• Information hiding 信息隐藏

• Polymorphism 多态性

Object and Programs

Scanner scan = new Scanner(System.in);
int width;
System.out.println("the width of the room");
width = scan.nextInt();

image

image

1. class

2. ClassName

3. access specifier（访问说明符：用于指定类成员的访问权限的关键字，如public、private和protected）

4. attributes

5. methods

6. one method same with class name (like __init__ in python)

Classes and Objects naming conventions

Class: upper camel case Variable: lower camel case

• getter and setter

public String getName(){
    return name;
}

public void setTutor(String name){
    tutor = name;
}

The Default Constructor

Object References

Array of objects