Studying programming

Upcasting을 이용하면 부모객체로 부터 상속받은 메서드를 사용할 수 있게된다. 즉, 단 하나의 부모클래스의 객체(PhoneInfo)로 여러가지 자식 메서드(univPhoneInfo, companyPhoneInfo, friendPhoneInfo)를 검색할 수 있는 장점이 있다. Example I public class PhoneInfo { String name; String phoneNum; public PhoneInfo(String name, String num){ this.name = name; phoneNum = num; } public void showInfo(){ System.out.println("name: " + name); System.out.println("phone: " + phon..

Upcasting Upcasting is casting from a subclass to superclass. When a superclass variable contains a reference to a subclass object, and that reference is used to call a method, the subclass version of the method is called. Student s = new Student (); Person p = (person)s; ↓ Person p = new Student();Reference variable object Upcasting happens if you want to reuse your code that knows about the su..