编写Java程序，使用while循环语句计算1+1/2!+1/3!···1/20!之和。

package JavaPractice;public class WhileTest{public static void main(String[] args){double x=1;double y=1;double z=0;double sum=0;while(x<=20){y=y*x;z=1/y;sum=sum+z;x++;}System.out.println("Total of '1 + 1/2! + 1/3! + ... + 1/20!' is: "+sum+".");}}

输出：

Total of '1 + 1/2! + 1/3! + ... + 1/20!' is: 1.7182818284590455.