1.if语句的学习
package if_Demo;
import java.util.Scanner;
public class biaodashi {
public static void main(String[] args) {
int x=1;
if(x>1){
System.out.println("yes");
}
else{
System.out.println("no");
}
int a=3,b;
/*if(a>1)
b=100;
else
b=200;
System.out.println("b="+b);
b=(a>1)? 100:200;
System.out.println("b="+b);
int q=3;
if(q>1){
System.out.println("a");
}
else if(q>2){
System.out.println("b");
}
else if(q>3){
System.out.println("c");
}
else{
System.out.println();
}*/
/*int week;
while(1==1){
Scanner scanner=new Scanner(System.in);
System.out.println("请输入数字：");
week=scanner.nextInt();
if (week==1){
System.out.println("星期一");
}
else if(week==2){
System.out.println("星期2");
}
else if(week==3){
System.out.println("星期3");
}
else if(week==4){
System.out.println("星期4");
}
else if(week==5){
System.out.println("星期5");
}
else if(week==6){
System.out.println("星期6");
}
else if(week==7){
System.out.println("星期7");
}
else{
System.out.println("请输入1~7的数字");
}
}*/
/*一年有Ⅳ季
* 春节345
* 夏季678
* 秋季91011
* 冬季1212
* 根据输入的月份输出对应的年份
*/
int week ;
while(1==1){
Scanner scanner=new Scanner(System.in);
System.out.println("请输入月份");
week=scanner.nextInt();
/*if(week==3 || week==5 || week==4){
System.out.println("春季");
}
if(week==6 || week==7|| week==8){
System.out.println("夏季");
}
if(week==9 || week==10 || week==11){
System.out.println("秋季");
}
if(week==12 || week==1 || week==2){
System.out.println("冬季");
}
else{
System.out.println("没有对应的季节");
}*/
if(week>=3 && week<=5){
System.out.println("春季");
}
if(week>=6 && week<=8){
System.out.println("夏季");
}
if(week>=9 && week<=11){
System.out.println("秋季");
}
if(week>=12 && week<=2){
System.out.println("冬季");
}
else if(week<1 ||week>12){
System.out.println("没有对应的季节");
}
}
}
}
2.swich语句的学习
package switch_Demo;
import java.util.Scanner;
public class Switch {
public static void main(String[] args) {
/*int x=3;
switch(x){
case 1:
System.out.println("a");
break;
case 4:
System.out.println("b");
break;
case 5:
System.out.println("c");
break;
case 2:
System.out.println("d");
break;
case 3:
System.out.println("e");
break;*/
/*int a=4,b=2;
char opr='-';
switch(opr){
default:
System.out.println("A");
case '+':
System.out.println("A+B");
//break;
case '-':
System.out.println("A-B");
//break;
case '*':
System.out.println("A*B");
//break;
case '/':
System.out.println("A/B");
break;
}*/
int week ;
while(1==1){
Scanner scanner=new Scanner(System.in);
System.out.println("请输入月份");
week=scanner.nextInt();
/*switch(week){
case 1:
System.out.println("星期一");
break;
case 2:
System.out.println("星期二");
break;
case 3:
System.out.println("星期三");
break;
case 4:
System.out.println("星期四");
break;
case 5:
System.out.println("星期五");
break;
case 6:
System.out.println("星期六");
break;
case 7:
System.out.println("星期七");
break;
default:
System.out.println("Error!!!");
}*/
switch(week){
case 3:
case 4:
case 5:
System.out.println("春节");
break;
case 6:
case 7:
case 8:
System.out.println("夏节");
break;
case 9:
case 10:
case 11:
System.out.println("秋节");
break;
case 12:
case 1:
case 2:
System.out.println("冬节");
break;
default:
System.out.println("Error!请输入1~12.。。。");
}
}
}
}
3.While循环的使用
package While_Demo;
public class whlie_xuhuan {
public static void main(String[] args) {
int x=1;
while(x<3){
System.out.println("x="+x);
x++;
}
int y=1;
do{
System.out.println(y);
y++;
}
while(y<1);
/*获取1~10的和
*
*/
int a=1;//记录参与加法的数据
int sum=0;//记录每一次的和
while(a<=100){
sum=sum+a;
a++;
}
System.out.println(sum);
}
}
4.while实战
package While_Demo;
public class while_Test {
public static void main(String[] args) {
/*练习：
* 1~100之间的6的倍数出现的次数
* 数，a
* 6的倍数的数b
* 次数c
*
*
*/
int a=1;
int sum=0;
while(a<=100)
{
if(a%6==0)
sum++;
a++;
}
System.out.println(sum);
}
}