test

測試，應該可以發

public static void main(String[] args){
  double f2,f1=2.55;
      f2=2.25;
          System.out.println("和="+(f1+f2));
          System.out.println("差="+(f1-f2));
          System.out.println("積="+(f1*f2));
          System.out.println("商="+(f1/f2));
       System.out.println("                ");
        double f3=2.5;
        int f4=4;
          System.out.println("和="+(f4+f3));
          System.out.println("差="+(f3-f4));
          System.out.println("積="+(f3*f4));
          System.out.println("商="+(f3/f4));
         
        System.out.println("                ");