EduCoder Java程序设计---Java面向对象（一） - 类与对象 答案

第1关：什么是类，如何创建类

package step1;

public class Test {
	public static void main(String[] args) {
		//创建Dog对象
		//设置Dog对象的属性
		Dog wuhuarou = new Dog();
		wuhuarou.name = "五花肉";
		wuhuarou.color  = "棕色";
		wuhuarou.variety = "阿拉斯加"; 
		
		
		//输出小狗的属性
		System.out.println("名字：" + wuhuarou.name    + "，毛色：" +  wuhuarou.color  + "，品种：" + wuhuarou.variety );
		
		//调用方法
		wuhuarou.eat();
		wuhuarou.run();
		
	}
}

//在这里定义Dog类
class Dog{
	String name;
	String color;
	String variety;
	void eat(){
		System.out.println("啃骨头");
	}
	void run(){
		System.out.println("叼着骨头跑");

	}
}

第2关：构造方法

package step2;

import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String name = sc.next();
		String sex = sc.next();
		
		//分别使用两种构造器来创建Person对象  
		Person  person1 = new Person();
		Person  person2 = new Person(name,sex);
		
		
		
	}
}

//创建Person对象，并创建两种构造方法
 class Person{
	String name;
	String sex;

	public Person(){
		System.out.println("一个人被创建了");
	}
	public Person(String pername ,String persex){
		name = pername;
		sex = persex;

		System.out.print("姓名："+name+"，"+"性别："+sex+"，被创建了");
	}
}

第3关：选择题

 

第4关：This关键字

package step3;

import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String name = sc.next();
		int age = sc.nextInt();
		String sex = sc.next();
		Person p = new Person(name,age,sex);
		p.display();
	}
}

class Person{
	String name = "张三";
	int age = 18; 
	String sex = "男";
// 请在此编写代码
/********** Begin **********/	
	public Person(String name,int age,String sex){
		this(age);
		this.name = name;
		this.sex = sex;
	}
	
	public Person(int age){
		this.age = age;
	}
/********** End **********/	
	
	public void display(){
		// String name = "李四";
		// int age = 11;
		// String sex = "男";
		System.out.println("name：" + name);
		System.out.println("age：" + age);
		System.out.println("sex：" + sex);
	}
}

第5关：类与对象练习

package step4;

import java.util.Scanner;

public class Test {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String theMa = sc.next();
		int quantity = sc.nextInt();
		boolean likeSoup = sc.nextBoolean();

		//使用三个参数的构造方法创建WuMingFen对象  取名 f1
		//使用两个参数的构造方法创建WuMingFen对象  取名 f2
		//使用无参构造方法创建WuMingFen对象  取名 f3
		WuMingFen f1 = new WuMingFen(theMa,quantity,likeSoup);
		WuMingFen f2 = new WuMingFen(theMa,quantity);
		WuMingFen f3 = new WuMingFen();

		f3.theMa = "酸辣";
		f3.quantity = 2;
		f3.likeSoup = true;

		//分别调用三个类的 check方法
		f1.check();
		f2.check();
		f3.check();
		
	}
}

		//在这里添加包名  step4
package step4;
		//创建类 添加属性和方法
		public class WuMingFen {
			String theMa;
			int quantity;
			boolean likeSoup;


			public WuMingFen(String theMa ,int quantity ,boolean likeSoup){
				this.theMa = theMa;
				this.quantity = quantity;
				this.likeSoup = likeSoup;
			}

			public WuMingFen(String theMa, int quantity){
				this.theMa = theMa;
				this.quantity = quantity;
			}
			public WuMingFen(){

			}
			public void check(){
				System.out.println("面码：" + theMa + "，粉的份量：" + quantity + "两，是否带汤："+ likeSoup);
			}

		}

第6关：static关键字

 

package step5;

public class Test {
	
	static String name = "楚留香";
	
	public static void hello(){
		System.out.println("hello educoder");
	}
	public static void main(String[] args) {
		hello();
		System.out.println("我叫" + name);
		study();
	}
	
	public static void study(){
		System.out.println("我喜欢在educoder上学习java");
	}
	
}

第7关：选择题