java 第七次作业

package wen;

 

public class paixu {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

        int x[]= {1,5,7,3,2,9,4};

        paixu(x);

        for(int i=0;i<x.length;i++) {

         System.out.println(x[i]);

        }

}

 

public static void paixu(int a[]) {

for(int i=0;i<a.length-1;i++) {

for (int j=0;j<a.length-1-i;j++) {

if(a[j]>a[j+1]) {

int temp=a[j];

a[j]=a[j+1];

a[j+1]=temp;

}

}

}

 

}

}

 2.编写一个方法，求整数n的阶乘，例如5的阶乘是1*2*3*4*5。 [必做题]

package wen;

 

public class jc {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

int sum1=jc(5);

System.out.println(sum1);

}

public static int jc(int n) {

int sum=1;

for(int i=1;i<=n;i++) {

sum*=i;

}

return sum;

}

 

}

 

3.编写一个方法，判断该年份是平年还是闰年。[必做题]

 

package wen;

 

import java.util.Scanner;

 

public class year {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

        year();

}

public static void year() {

Scanner input=new Scanner(System.in);

System.out.println("输入年份：");

int year=input.nextInt();

if(year%4==0&&year%100!=0||year%400==0) {

System.out.println(year+"是闰年");

}else {

System.out.println(year+"是平年");

}

 

}

 

}

 4.使用方法重载，定义一个可以求出圆形面积和矩形面积的方法getArea 

package wen;

 

public class llt {

 

public static double Area(double a,double b) {

return a*b;

}

public static double Area(double r) {

return r*r*Math.PI;

}

public static void main(String[] args) {

System.out.println(Area(5,8));

System.out.println(Area(10));

}

 

}

 5.定义一个笔记本类，该类有颜色(char) 和cpu型号(int) 两个属性。[必做题]
（1）无参和有参的两个构造方法;有参构造方法可以在创建对象的同时为每个属性赋值;
（2） 输出笔记本信息的方法
（3） 然后编写一个测试类，测试笔记本类的各个方法。

package wen;

 

public class ComputerTest {

 

public static void main(String[] args) {

// TODO Auto-generated method stub

Computer c1=new Computer('黑',24);

c1.showComputer();

Computer c2=new Computer('红',32);

        c2.showComputer();

}

 

}

 

class Computer {

private char color;

private int cpuNum;

 

public Computer() {

 

}

 

public Computer(char color,int cpuNum) {

this.color=color;

this.cpuNum=cpuNum;

}

public char getColor() {

return color;

}

 

public void setColor(char color) {

this.color=color;

}

 

public int getcpuNum() {

return cpuNum;

}

 

public void setcpuNum(int cpuNum) {

this.cpuNum=cpuNum;

}

public void showComputer() {

System.out.println("笔记本的颜色："+getColor());

System.out.println("笔记本的CPU型号："+getcpuNum());

}

}