代码:
public class phoneTest {
public static void main(String[] args) {
phone [] arr = new phone[3];
phone p1 = new phone("华为",6999,"白色");
phone p2 = new phone("vivo",4999,"蓝色");
phone p3 = new phone("苹果",7999,"黑色");
arr[0]=p1;
arr[1]=p2;
arr[2]=p3;
double avg = (p1.getPrice()+ p2.getPrice()+p3.getPrice())/3;
System.out.println(avg);
}
}
public class phone {
private String brand;
private double price;
private String color;
public phone() {
}
public phone(String brand, double price, String color) {
this.brand = brand;
this.price = price;
this.color = color;
}
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
}
运行结果:
代码:
public class girlTest {
public static void main(String[] args) {
girl [] arr = new girl[4];
girl g1 = new girl("小红",18,'女',"跳舞");
girl g2 = new girl("小芳",22,'女',"唱歌");
girl g3 = new girl("小刘",23,'女',"骑车");
girl g4 = new girl("小美",19,'女',"爬山");
arr[0]=g1;
arr[1]=g2;
arr[2]=g3;
arr[3]=g4;
double sum=0;
for(int i=0;i<arr.length;i++){
girl girl=arr[i];
sum+=girl.getOld();
}
double avg = sum/arr.length;
System.out.println(avg);
int count=0;//统计思想
for(int i=0;i<arr.length;i++){
girl girl=arr[i];
if(girl.getOld()<avg) {
count++;
System.out.println(girl.getName() + "," + girl.getOld() + "," + girl.getHobby() + "," + girl.getSex());
}
}
System.out.println("有"+count+"个");
}
}
public class girl {
private String name;
private int old;
private char sex;
private String hobby;
public girl() {
}
public girl(String name, int old, char sex, String hobby) {
this.name = name;
this.old = old;
this.sex = sex;
this.hobby = hobby;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getOld() {
return old;
}
public void setOld(int old) {
this.old = old;
}
public char getSex() {
return sex;
}
public void setSex(char sex) {
this.sex = sex;
}
public String getHobby() {
return hobby;
}
public void setHobby(String hobby) {
this.hobby = hobby;
}
}
代码结果:
自己写的代码:
import java.sql.SQLOutput;
import java.util.Scanner;
public class studentTest {
public static void main(String[] args) {
Scanner input = new Scanner (System.in);
student [] arr = new student[3];
student s1 = new student("heima001","小白",19);
student s2 = new student("heima002","小黑",19);
student s3 = new student();
arr[0]=s1;
arr[1]=s2;
arr[2]=s3;
System.out.println("输入第3个同学的学号:");
boolean flag = true;
do {
String n = input.next();
if ((!n.equals(s1.getNov())) && (!n.equals(s2.getNov()))) {
s3.setNov(n);
flag=false;
} else {
System.out.println("该用户已存在,输入失败,请重新输入:");
}
}while(flag);
System.out.println("输入第3个同学的名字:");
String m = input.next();
s3.setName(m);
System.out.println("输入第3个同学的年龄:");
int q = input.nextInt();
s3.setAge(q);
for(int i=0;i<arr.length;i++){
student student = arr[i];
System.out.println(student.getNov()+","+student.getName()+","+student.getAge());
}
System.out.println("请输入要删除的学生的学号:");
String p = input.next();
int count =0;
for(int j=0;j< arr.length;j++){
student student = arr[j];
if(p.equals(student.getNov())) {
student.setAge(0);
student.setName(null);
student.setNov(null);
System.out.println("删除成功");
break;
}else{
count++;
}
if(count==arr.length){
System.out.println("删除失败");
}
}
for(int i=0;i<arr.length;i++){
student student = arr[i];
System.out.println(student.getNov()+","+student.getName()+","+student.getAge());
}
for(int i=0;i<arr.length;i++){
student student = arr[i];
if(student.getNov()=="heima002"){
int age =student.getAge()+1;
student.setAge(age);
System.out.println(student.getAge());
}
//System.out.println(student.getNov()+","+student.getName()+","+student.getAge());
}
}
}
public class student {
private String Nov;
private String name;
private int age;
public student() {
}
public student(String nov, String name, int age) {
Nov = nov;
this.name = name;
this.age = age;
}
public String getNov() {
return Nov;
}
public void setNov(String nov) {
Nov = nov;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
缺少如果数组满了要添加对象进去的判断:
1、判断id是否重复:
2、判断数组是否已满:
3、如果数组已经满了,那么创建一个新数组,并且将老数组里的元素复制进去:
4、进行添加和判断操作
5、打印元素的时候,需要分两种情况讨论,一个是添加成功的数组,一个是没有添加成功的数组,可以写一个方法:
6、在上面调用遍历的方法:
若数组不满,删除stu3,那么在数组中事null,但是不能通过null直接使用遍历,相当于用null调用了其他方法,会爆粗,
所以对判断唯一性的方法进行修改:需要判断stu是否为null
补充:拆分题干:
7、对于判断id写一个方法:
8、删除id并遍历:
9、给指定那个学号的学生年龄加一