Java 计算阶乘和的一类 案例“ja”： System.out.println（“Ievadiet vardu”）； 字符串x=input.next（）； n=x.长度（）； { 长期事实； 事实=1； 对于（inti=1；i

您可以添加如下

getFactorialSum

方法

case "ja":
          System.out.println("Ievadiet vardu");
          String x = input.next();                  
          n = x.length();    
          {         
              long fact;
              fact = 1;         
              for (int i = 1; i <= n; i++) {
                  fact *= i;
                  sum += fact;
              }       
          }
          break;
case "ne":
          Scanner in = new Scanner(System.in);            
          System.out.println("Ievadiet ciparu");        
          n = in.nextInt();     
          if ( n < 0 ){
              System.out.println("Ciparam jabut pozitivam.");
          }     
          {         
               long fact;
               fact = 1;         
               for (int i = 1; i <= n; i++) {
                   fact *= i;
                   sum += fact;
               }     
          }
          break;

// private means only this class can call the method.
private static long getFactorialSum(int n) {
  long fact = 1;
  long sum = 0;
  for (int i = 1; i <= n; i++) {
    fact *= i;
    sum += fact;
  }
  return sum;
}

String x = input.next();                  
n = x.length();
long factorialSum = getFactorialSum(n);