SCJP題庫第042題

1. class A{

2.   public String doit(int x, int y){

3.     return "a";

4.   }

5.

6.   public String doit(int... vals){

7.   return "b";

8.   }

9. }

Given:

25. A a = new A();

26. System.out.println(a.doit(4, 5));

What is the result?

A. Line 26 prints "a" to System.out.

B. Line 26 prints "b" to System.out.

C. An exception is thrown at runtime.

D. Compilation of class A will fail due to an error in line 6.

Ans:A

解說:

方法呼叫代入二個整數，方法是以“明確”的二個整數參數宣告的方法為優先選取。

 

若要輸出b(選擇第6行)，則建議的程式可改為

class A{
   public String doit(int x, int y, int c){
     return "a";
   }

   public String doit(int... vals){
     return "b";
   }

   public static void main(String[] args){
     A a = new A();
     System.out.println(a.doit(4, 5));
   }
 }