Type Casting

https://www.w3schools.com/java/java_type_casting.asp

W3Schools.com

 

특정 원시타입(Primitive Type)을 다른 타입으로 전환하는 기술

Java에는 2가지 캐스팅 방식이 존재한다.

• 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 Casting의 예

public class Main {
  public static void main(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 Casting의 예

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
  }
}