[OCAJP]從命令列傳入參數2

Given the code in a file Traveler.java:

class Tours {

    public static void main(String[] args) {
        System.out.print("Happy Journey! " + args[1]);
    }
}

public class Traveler {

    public static void main(String[] args) {
        Tours.main(args);
    }
}

And the commands:

What is the result?

A.

B.

C. An exception is thrown at runtime
D. The program fails to execute due to a runtime error

題解

程式第11行，呼叫Tours類別的main靜態方法，並把main的args參數作為引數繼續傳遞過去。在CLI介面下傳入給Java程式的參數索引值是從0開始的，題目的要傳給Traveler類別的參數是「Java Duke」，因此args[0]="Java"，args[1]="Duke"。