// 2 step initialization
int[] intArr;           // declaration
intArr = new int[2];    // initialization with null's

// direct initialization with nulls
int[] intArr = new int[2];

// direct initialization with values
int[] intArr = {1,2,45};

// 2 step initialization
int[][] matrix;           // declaration
matrix = new int[][];     // initialization

// direct initialization with null's
int[][] matrix = new int[2][4]; 

// direct initialization with values