学习视频:https://www.bilibili.com/video/BV18J411W7cE?p=1
switch结构:
case穿透:
判断一个月为哪一个季节:
switch(month){
case 1 :
case 2 :
case 12 :
System.out.println("冬季");
break;
case 3 :
case 4 :
case 5 :
System.out.println("春季");
break;
case 6:
case 7 :
case 8 :
System.out.println("夏季");
break;
case 9 :
case 10 :
case 11 :
System.out.println("秋季");
break;
deafult:
System.out.println("输入月份有误");
}
水仙花数:
//水仙花数
public class demo{
public static void main(String[] args){
int i,j,k;
int count = 0;
for(int a = 100 ; a < 1000 ; a++ ){
i = a % 10;
j = a / 100;
k = a / 10 - j*10 ;
if(a == i*i*i + j*j*j + k*k*k){
System.out.println(a);
count ++;
}
}
//输出水仙花数的个数
System.out.println("水仙花数的个数为:"+count);
}
}
跳转控制语句:
break 终止循环体内容的执行
continue 跳过某一次的循环,继续执行下一次
eg:
for (int i = 1 ; i < 5 ; i++){
if(i % 2 == 0){
break;
//continue;
}
}
Random:
作用:产生一个随机数
1、导入包
import java.util.Random;
2、创建对象
Random r = new Random();
3、获取随机数
int number = r.nextInt(10);
import java.util.Random;
public class demo{
public static void main(String[] args){
Random r = new Random();
int number = r.nextInt(10);
System.out.println(number);
}
}
注意:
int number = r.nextInt(10); //范围为0-9
int number1 = r.nextInt(10)+1; //范围为0-10
猜数字游戏:
import java.util.Random;
import java.util.Scanner;
public class demo{
public static void main(String[] args){
Random r = new Random();
Scanner sc = new Scanner(System.in);
int number = r.nextInt(100);
while(true){
int i = sc.nextInt();
if(number == i){
System.out.println("猜测正确数字为:" + i);
break;
}
else if(number < i){
System.out.println("猜大了,请继续猜测");
}
else{
System.out.println("猜小了,请继续猜测");
}
}
}
}