Tag: 定向

在父类之间来回转换后，子对象是否会丢失其唯一属性

考虑以下类： public class Phone { private boolean has3g; public boolean has3g() { return has3g; } public void setHas3g(boolean newVal) { has3g = newVal; } } public class Blackberry extends Phone { private boolean hasKeyboard; public boolean hasKeyboard() { return hasKeyboard; } public void setHasKeyboard(boolean newVal) { hasKeyboard = newVal; } } 如果我要创建一个Blackberry实例，将其转换为Phone对象，然后将其转换回Blackberry ，原始Blackberry对象是否会丢失其成员变量？ 例如： Blackbery […]