类型转换的前提:父类引用指向子类的对象
父类 p = new 子类();
子类转换父类,向上转型
父类转换子类,向下转型
类型转换的作用:方便方法的调用,减少重复的代码
package com.jiemyx.oop.demo10;
public class Person {
}
package com.jiemyx.oop.demo10;
public class Student extends Person{
public void study(){
}
}
package com.jiemyx.oop.demo10;
public class Application {
public static void main(String[] args) {
// 高 低
//类之间的转换:父类 子类
//父类转换为子类,强制转换
Person p = new Student();
Student s = (Student)p;
s.study();
//或者
((Student)p).study();
//子类转换为父类
Student x = new Student();
x.study();
Person p1 = x;
//p1.study(); //报错
}
}