个回答

• 乐观的z小筱

  2015-07-11 18:41:30

  
  

  public static void main(String[] args){
          int num = 999;
          int count = 0;
          while(num>1){
              num=num/10;
              count++;
          }
          System.out.println("它是一个"+count+"位数");
          }

  
  

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