多重if_else:
package com.dengchaoqun.ht;
public class Double_For02 {
/**
*
* 打印乘法表
*/
public static void main(String[] args) {
for (int i = 1; i < 10; i++) {
for (int j = 1; j <= i; j++) {
int a = i * j;
System.out.print(i + "*" + j + "=" + a + "\t");
}
System.out.println();
}
}
}
switch_case:
package com.dengchaoqun.ht;
import java.util.Scanner;
public class Leap_yearOrCommon_year {
public static void main(String[] args) {
Scanner scan=new Scanner(System.in);
int year;
int month;//用来输入月份
System.out.println("请输入年份:");
year=scan.nextInt();
System.out.println("请输入月份:");
month=scan.nextInt();
//判断是否为闰年
if((year%4==0&&year%100!=0)||(year%400==0))
{
System.out.println(year+"年是闰年!");
}
else
{
System.out.println(year+"年是平年!");
}
//输出月份的天数
switch(month) //switch-case语句输出月份的天数
{
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
System.out.println(year+"年"+month+"月是31天!");
break;
//判断是否是闰年的二月还是平年的二月
case 2:
if((year%4==0&&year%100!=0)||(year%400==0))
{
System.out.println(year+"年"+month+"月是29天!");
break;
}
else
{
System.out.println(year+"年"+month+"月是28天!");
break;
}
case 4:
case 6:
case 9:
case 11:
System.out.println(year+"年"+month+"月是30天!");
break;
default:
System.out.println("请输入正确的年份和月份!");
}
scan.close();
}
}
while:
package com.dengchaoqun.ht;
public class While {
/**
*
* 使用while单循环求1!+2!+...+7!
*/
public static void main(String[] args) {
// TODO 自动生成的方法存根
int i=1;
int j=1;
int sum=0;
while(i<8)
{
j=i*j;
sum+=j;
i++;
}
System.out.println("1!+2!+...+7!="+sum);
}
}
do_while:
package com.dengchaoqun.ht;
import java.util.Scanner;
public class Do_while_02 {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner scan = new Scanner(System.in);
do {
int n = 0;
System.out.println("1.注册");
System.out.println("2.登录");
System.out.println("0.退出");
System.out.println("请选择输入项:");
n = scan.nextInt();
if (n == 0) {
System.out.println("您选择了退出");
break;
} else if (n == 1) {
System.out.println("您选择了登录");
} else if (n == 2) {
System.out.println("您选择了退出");
} else {
System.out.println("您选择了错误");
}
} while (true);
scan.close();
}
}
for:
package com.dengchaoqun.ht;
public class Double_For02 {
/**
*
* 打印乘法表
*/
public static void main(String[] args) {
for (int i = 1; i < 10; i++) {
for (int j = 1; j <= i; j++) {
int a = i * j;
System.out.print(i + "*" + j + "=" + a + "\t");
}
System.out.println();
}
}
}