流程控制
复合语句:{}
条件语句
//one
if(){
}
else{
}
//tow
if(){}
//three
if(){
}
else if(){
}
//four
switch(表达式){
case 常量1: {
}break;
case 常量2: {
}break;
case 常量3: {
}break;
default:
{}
[break;]
……
}
循环语句:
while(){
}
do{
}while();
for()
{
}
循环语句的跳出:continue,break
用while循环计算1+1/2!+1/3!…1/20!
package first;
public class a {
public static void main(String[] args) {
// TODO Auto-generated method stub
float sum = 0;
int i=1;
long j;
int k;
while(i<=20) {
j=1;
for(k=1;k<=i;k++) {
j*=k;
}
sum+=(1.0/j);
i++;
}
System.out.println(sum);
}
}
应用if语句判断某一年是否为闰年
package first;
import java.util.Scanner;
public class a {
public static void main(String[] args) {
// TODO Auto-generated method stub
float sum = 0;
int year;
Scanner cin=new Scanner(System.in);
year=cin.nextInt();
if((year%100!=0&&year%4==0)||year%400==0)
System.out.println("闰年");
else
System.out.println("平年");
}
}