Meaning of "int... j"

[Suresh Rajadurai]

Hi,

I am preparing for Java certification, I came across a method declaration in a mock question.

public void methodX(int i, int... j)

Can anybody explain the meaning of "int... j"?

Thanks.

[Freddy Wong]

Take a look at this article.
http://java.sun.com/j2se/1.5.0/docs/guide/language/varargs.html

[Rob Spoor]

In short, it means "int[] i" with the difference that when calling this method, you don't need to explicitly create the array.

For example:

public void doSomething(int[] array)
{
    doSomethingElse(array);
}
 
public void doSomethingElse(int... varargs)
{
    for (int i = 0; i < varargs.length; i++)
    {
        System.out.println(varargs[i]);
    }
    // and yes, the for-each loop is also available
}
 
public static void main(String[] args)
{
    int[] array = {1, 2, 3};
    // array needed
    doSomething(array);
    // array is allowed
    doSomethingElse(array);
    // but not necessary
    doSomethinhElse(1, 2, 3);
    doSomethingElse(1, 2);
    doSomethingElse(1);
    doSomethingElse();
}

In the last four lines, the compiler creates an array for you. In the last case, this will be an empty array.