Prerequisite :
Arrays in Java
While working with arrays we have to do 3 tasks namely declaration, creation, initialization or Assignment.
Declaration of array :
int[] arr;
Creation of array :
// Here we create an array of size 3
int[] arr = new int[3];
Initialization of array :
arr[0] = 1;
arr[1] = 2;
arr[3] = 3;
int intArray[]; // declaring array
intArray = new int[20]; // allocating memory to array
Some important facts while assigning elements to the array:
- For primitive data types : In case of primitive type arrays, as array elements we can provide any type which can be implicitly promoted to the declared type array. Apart from that, if we are trying to use any other data-types then we will get compile-time error saying possible loss of precision.
Output:
108
Output:
possible loss of precision.
Output:
error: incompatible types: possible lossy conversion from long to char
error: incompatible types: possible lossy conversion from double to char
- Object type Arrays : If we are creating object type arrays then the elements of that arrays can be either declared type objects or it can be child class object.
Output:
10
20.5
Output:
Compile-time error(incompatible types)
Output:
error: incompatible types: char cannot be converted to Number
error: incompatible types: String cannot be converted to Number
- Interface type array : For interface type array, we can assign elements as its implementation class objects.
