大二软件工程学生,初学Java,小小小小程序,练个手。想认识新朋友。☀☀☀
do-while
/**
* 用do-while计算1+1/2!+1/3!+……的前20项的和
* @author Rigel
*
*/
public class Add2 {
public static void main(String[] args) {
int i = 1, a = 1;
double sum = 0,b = 0;
do {
a = i * a;
b = 1.0 / a;
sum = sum + b;
i++;
}while(i <= 20);
System.out.println(sum);
}
}
for循环
/**
* 用for循环计算1+1/2!+1/3!+……的前20项的和
* @author Rigel
*
*/
public class Add1 {
public static void main(String[] args) {
int i = 1, a = 1;
double sum = 0,b = 0;
for(i = 1; i <= 20; i++) {
a = i * a;
b = 1.0 / a;
sum = sum + b;
}
System.out.println(sum);
}
}