the main class in a java source file?

Question

im new to java.

the standard code that is created after i created a new project in netbeans is:

package helloworldapp;

public class Main {

    public static void main(String[] args) {
        int[] array = new int[10];
        array[9] = 1;

        System.out.println(array[9]);
    }
}

so you see that it uses the System class, but i dont see that class has been imported. Is there another code somewhere that does that? How can i use it if its not imported.

Answer 1

The System class is, along with everything else in java.lang, imported automatically. Other classes you probably use that are automagically imported include String and Exception.

Answer 2

Additional info:

How can i use it if its not imported.

you can use any class in another package, without importing it, by using the fully qualified name. Example:

    java.util.Date now = new java.util.Date();

instead of

import java.util.Date;  // or java.util.*;
...
    Date now = new Date();

Update:
import is only used at compile time to determine the fully qualified name of classes.