第七次作业
1.编写一个方法,实现冒泡排序(由小到大),并调用该方法
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());
}
}