Type Casting

Type Casting in Java

1. When you want to convert a value from A type to B type that is called Type Casting.

2. There are two type of Type Casting:

i. Narrowing / Explicit Conversion / Downcasting

ii. Widening / Implicit Conversion / Upcasting

i. Narrowing

• Narrowing means when you convert a large data type into small data type.
• When you follow this direction that is called Narrowing.
  double -> float -> long -> int -> short -> byte
• It is also called Explicit conversion.
• It is also called Downcasting.
• Example

                  //this type of conversion is called Explicit or Narrowing.
                  int i=10;
                  byte b=(byte)i;
  
                  String s="12";
                  int k=Integer.parseInt(s);
  
                  //In terms of Inheritence we use Upcasting and Downcasting word.
                  //when child get own object from parent class that is called Downcasting
                  Dog dog=(Dog)animal;
          

ii. Widening

• Widening means when you convert a small data type into large data type.
• When you follow this direction that is called Widening.
  byte -> short -> int -> long -> loat -> double
• It is also called Implicit conversion.
• It is also called Upcasting.
• Example

                  //this type of conversion is called Implicit or Widening.
                  byte i=10;
                  int b=i;
  
                  //when parent hold object of own child class that is called Upcasting.
                  Animal animal=new Dog();
          

There are some rules which supported by default in Java:

byte + byte = int

byte + anynumber = int

byte + short = int

short + short = int

char + char = int

int + int = int

int + long = long

long + float = float

float + double = double

String + anything = String