如何设置命令行参数存储的数组大小？

Question

I basically want to store my user input in an array of size 3. When I seem to put 3 in the main (String [3] args), it doesn't seem to do what I want. How do I resolve this issue?

If it helps, the exercise is asking me to: Fill in the class method main of class Ex4 with code that create an array of size 3 containing strings and fills it with command line arguments.

Thanks.

 public class Ex4 {
 public static void main(String[] args) 
 {
 if (args.length == 1)
 {
     System.out.println(args[0]);
 }

 else if (args.length == 2 || args.length == 3)
 {
     System.out.println(args[0]);
     System.out.println(args[1]);
 }

 else 
    System.out.println("Too many arguments");
}
}

Answer 1

You can't control the size of the array passed to the main method. It will automatically be allocated with the size of the arguments passed to the program.

Answer 2

You get it backwards.

You define the size of that array implicitly, by the number of arguments that you pass when starting the JVM.

At runtime, within your Java code you can only check the actual length of that array. For example to give an error message to the user telling him about the required number of arguments and their meaning.