package homework;
public class SumNum {
public static void main(String[] args) {
int sumFactorial = 0;
final int NUMBER = 10;//一共十个数字
/*
* 累加阶乘
* */
for(int i = 1;i<=NUMBER;i++) {
sumFactorial += factorial(i);
}
System.out.println(sumFactorial);
}
/*
* 计算数字的阶乘
* */
public static int factorial(int num) {
int sum = 1;
for(int i=1; i<=num; i++) {
sum *= i;
}
return sum;
}
}
第二题
package homework;
public class Circle {
final static double PI = 3.14;//常量PI
double r; //圆的半径
double area; //圆的面积
double perimeter;//圆的周长
public Circle() {
this.r = 0;
}
public Circle(double r) {
this.r = r;
}
/*
* 返回面积
* */
public double getArea() {
this.area = PI * this.r * this.r;
return this.area;
}
/*
* 返回周长
* */
public double getPerimeter() {
this.perimeter = 2 * PI * r;
return this.perimeter;
}
/*
* 输出信息
* */
public void show() {
System.out.println("圆的半径=" + r);
System.out.println("圆的周长=" + getPerimeter());
System.out.println("圆的面积=" + getArea());
}
/*
* Test
* */
public static void main(String[] args) {
Circle myCircle = new Circle(3);
myCircle.show();
}
}
第三题
package homework;
public class Student {
String sNO; //学号
String sName; //姓名
String sSex; //性别
double sJava; //成绩
public Student(String XH, String XM, String XB, double CJ) {
this.sNO = XH;
this.sName = XM;
this.sSex = XB;
this.sJava = CJ;
}
/*
* 返回学号
* */
public String getNo() {
return("学号: " + sNO + " ");
}
/*
* 返回姓名
* */
public String getName() {
return("姓名: " + sName +" ");
}
/*
* 返回性别
* */
public String getSex() {
return("性别: " + sSex +" ");
}
/*
* 返回成绩
* */
public String getJava() {
return("成绩: " + sJava +" ");
}
public static void main(String[] args) {
Student liuLuFei = new Student("001","刘璐菲","男",99);
Student liJianYe = new Student("002","李建业","女",20);
Student liSan = new Student("003","李三","男",100);
Student liXiaoYe = new Student("004","李小业","女",10);
Student liErYe = new Student("005","李二业","男",18);
Student class1[]= {liuLuFei, liJianYe, liSan, liXiaoYe, liErYe};
/*
* 输出5为学生的信息
* */
for(int i=0; i< class1.length;i++) {
System.out.println(class1[i].getNo()+class1[i].getName()+class1[i].getSex()+class1[i].getJava());
}
/*
* 计算5位学生的平均成绩
* */
double sum = 0, ave = 0;
for(int i=0;i< class1.length;i++) {
sum += (double)class1[i].sJava;
}
ave = sum / class1.length;
System.out.println("平均成绩: " + ave);
/*
* 计算5为学生成绩的最大最小值
* */
double maxJava = 0, minJava = 100;
for(int i =0;i<class1.length;i++) {
if(class1[i].sJava > maxJava) {
maxJava = class1[i].sJava;
}
if(class1[i].sJava < minJava) {
minJava = class1[i].sJava;
}
}
System.out.println("最大成绩:" + maxJava);
System.out.println("最小成绩:" + minJava);
}
}