Java Type Casting

Type casting is when you assign a value of one primitive data type to another type.

In Java, there are two types of casting:

Widening Casting - (automatically) - converting a smaller type to a larger type size byte -> short -> char -> int -> long -> float -> double
Narrowing Casting - (manually) - converting a larger type to a smaller size type double -> float -> long -> int -> char -> short -> byte

Widening Casting

Widening casting is done automatically when passing a smaller size type to a larger size type:

Example

    
public classMain { 
               
public static voidmain(String[] args) {
int myInt = 9; 
double myDouble = myInt; // Automatic casting: int to double
                
System.out.println(myInt);      // Outputs 9 
System.out.println(myDouble);   // Outputs 9.0 
} 
}

Narrowing Casting

Narrowing casting must be done manually by placing the type in parentheses in front of the value:

Example

public class Main {
public static void main(String[] args) {
double myDouble = 9.78d;
int myInt = (int) myDouble; // Manual casting: double to int
                      
System.out.println(myDouble);   // Outputs 9.78
System.out.println(myInt);      // Outputs 9
}
 }