how to automatically construct array in java with size code example

Example 1: how to declare array java

int intArray[];    //declaring array
intArray = new int[20];  // allocating memory to array
//OR
int[] intArray = new int[20]; // combining both statements in one

Example 2: how to initialize array in java

int[] arr = new int[5];	 // integer array of size 5 you can also change data type