java 父类转换成子类的方法
/* 父类转换成子类的特点: 1:父类转换成子类不能自动完成 2:父类转换成子类的前提是父类的真身是这个子类 3:如果这个父类的真身是子类B,不能强制转换成子类A,只能转换成B. */ class Teacher2{ String name = “王鹏”; public void Teach(){ System.out.println(name+“在教课”); } } class JavaTeacher extends Teacher2{ public void Teach(){ System.out.println(name+“在ks”); } //read阅读 public void Read(){ System.out.println(name+“在图书馆看书”); } } class EnglishTeacher extends Teacher2{ public void Teach(){ System.out.println(name+“在教英语”); } } public class TestTeacher2{ public static void main(String[] args){ Teacher2 t = new JavaTeacher();
//t.name = "李静"; t.Teach(); //强制转换 ,把真身是JavaTeacher的父类转回JavaTeacher的子类 JavaTeacher jt = (JavaTeacher)t; jt.Read(); //3:如果这个父类的真身是子类B,不能强制转换成子类A,只能转换成B. Teacher2 e = new EnglishTeacher(); EnglishTeacher et = (EnglishTeacher)e; et.Teach(); }
}
