Java 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 sdaw; public class dwswas { public static void main(String[] args) { // TODO Auto-generated method stub int x[]= {5,7,13,15,21,63,40}; 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 sdaw; public class dwswas { 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 sdaw;
import java.util.Scanner;
public class dwswas {
public static void main(String[] args) {
// TODO Auto-generated method stub
nian();
}
public static void nian() {
Scanner input = new Scanner(System.in);
System.out.println("输入年份");
int year = input.nextInt();
if (year % 4 == 0 && year % 100 != 100 || year % 400 == 0) {
System.out.println("该年份为闰年");
} else {
System.out.println("该年份是平年");
}
}
}
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 sdaw; import java.util.Scanner; public class dwswas { public static void main(String[] args) { // TODO Auto-generated method stub getarea(2); getarea(2,4); } public static void getarea(double r) { double m=3.14; double area=m*r*r; System.out.printf("圆的面积是: %.2f",area); } public static void getarea(double a,double b) { double area=a*b; System.out.printf("矩形的面积是:%.2f",area); } }
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 sdaw; import java.util.Scanner; public class dwswas { public static void main(String[] args) { // TODO Auto-generated method stub Computer c1 = new Computer(); c1.showComputer(); Computer c2 = new Computer('白', 2048); 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()); } }