java - 如何减少该方法的重复性？

Question

这是我正在处理的代码(它是 CalculatorTester 类的一部分，是 Calculator 类的扩展):

 if (choice == 1) //Addition
    {
        System.out.println("Math Operation: Addition."); 
        System.out.println("Enter First Number."); 
        int a = in.nextInt(); 
        System.out.println("Enter Second Number."); 
        int b = in.nextInt(); 
        int endValue = c1.addition(a, b); 
        System.out.println("The Sum is: " + endValue + "."); 
    }
    else if (choice == 2)
    {
          ...More Code Here...
    }//end of if() 

Calculator对象内部的加法方法:

   public int addition(int a, int b)
   {
       endValue = a + b; 
       return endValue; 
   }//end of method addition() 

由于可以选择的不同操作数量众多，我总共有 5 个 if 语句，因此我该如何减少 if 语句的重复性？

谢谢!

Answer 1

先询问数字，后给出结果:

//user selects operation
System.out.println("Enter First Number."); 
int a = in.nextInt(); 
System.out.println("Enter Second Number."); 
int b = in.nextInt(); 

int endValue;
if (choice == 1) //Addition
    endValue = c1.addition(a, b); 
else if (choice == 2)
    endValue = c1.subtraction(a, b); 
else
    //throw exception since there was no endValue calculated

System.out.println("The result is: " + endValue + "."); 

您还可以使用 switch/case 代替 if/if else/else .