Arrays must be declared before you use them. : Array « Java Source And Data Type « SCJP

1. SCJP
2. Java Source And Data Type
3. Array

public class MainClass {
  public static void main(String[] argv) {
    int counts[]= null;
    boolean flags[];
    String names[];
    MyClass[][] things; // a two-dimensional array of objects
    System.out.println("counts = " + counts);

  }
}

class MyClass {
}