Declaring an Array of Primitives, and declaring an Array of Object References : 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[] key;  // Square brackets before name (recommended)
        int key []; // Square brackets after name (legal but less readable)

        System.out.println();
    }
}   

public class MainClass{
    public static void main(String[] argv){
        Thread[] threads;  // Recommended
        Thread threads1 []; // Legal but less readable
    }
}