Java 练习(继承性练习)

练习1

ManKind.java

package com.klvchen.exer;

public class ManKind {
	
	private int sex;     //性别
	private int salary;  //薪资
	
	public ManKind() {
		
	}

	public ManKind(int sex, int salary) {
		this.sex = sex;
		this.salary = salary;
	}

	public void manOrWoman() {
		if(sex == 1) {
			System.out.println("man");
		}else if(sex == 0) {
			System.out.println("woman");
		}
	}
	
	public void employeed() {
		String jobInfo = (salary == 0)? "no job": "job";
		System.out.println(jobInfo);
	}

	public int getSex() {
		return sex;
	}

	public void setSex(int sex) {
		this.sex = sex;
	}

	public int getSalary() {
		return salary;
	}

	public void setSalary(int salary) {
		this.salary = salary;
	}

}

Kids.java

package com.klvchen.exer;

public class Kids extends ManKind{
	private int yearsOld;
	
	public Kids() {
		
	}
	
	public Kids(int yearsOld) {
		this.yearsOld = yearsOld;
	}

	public void printAge() {
		System.out.println("I am " + yearsOld + " years old.");
	}

	public int getYearsOld() {
		return yearsOld;
	}

	public void setYearsOld(int yearsOld) {
		this.yearsOld = yearsOld;
	}

}

KidsTest.java

package com.klvchen.exer;

public class KidsTest {
	public static void main(String[] args) {
		
		Kids someKid = new Kids(12);
		
		someKid.printAge();
		
		someKid.setSalary(0);
		someKid.setSex(1);
		
		someKid.employeed();
		someKid.manOrWoman();
	}
}

运行结果:

练习2

Circle.java

package com.klvchen.exer1;

public class Circle {
	
	private double radius;   //半径
	
	public Circle() {
		radius = 1.0;
	}

	public double getRadius() {
		return radius;
	}

	public void setRadius(double radius) {
		this.radius = radius;
	}

	//返回圆的面积
	public double findArea() {
		return Math.PI * radius * radius;
	}
}

Cylinder.java

package com.klvchen.exer1;

public class Cylinder extends Circle{
	
	private double length;   //高
	
	public Cylinder() {
		length = 1.0;
	}

	public double getLength() {
		return length;
	}

	public void setLength(double length) {
		this.length = length;
	}

	//返回圆柱的体积
	public double findVolume() {
		return findArea() * getLength();
	}
}

CylinderTest.java

package com.klvchen.exer1;

public class CylinderTest {
	public static void main(String[] args) {
		
		Cylinder cy = new Cylinder();
		
		cy.setRadius(2.1);
		cy.setLength(3.4);
		double volume = cy.findVolume();
		System.out.println("圆柱的体积为: " + volume);
		
		double area = cy.findArea();
		System.out.println("底面圆的面积: " + area);
	}

}

运行结果: