Java的覆写操作实例分析

class Book
{
  String info = "Hello World." ;  // 如果加上private，1处的代码就会编译不过
}
class ComputerBook extends Book
{
  int info = 100 ;  // 属性名称相同
  public void print()
  {
    System.out.println(info) ;
    System.out.println(super.info) ;     // 1处代码
  }
}
public class OverrideData
{
  public static void main(String args[])
  {
    ComputerBook cb = new ComputerBook() ; // 实例化子类对象
    cb.print() ;
  }
}

class Person
{
  String name;
  int age;
  public String talk( )
  {
    return "I am " + this.name + ", I am " + this.age + " years old";
  }
}
class Student extends Person
{
  String school;
  public Student( String name, int age, String school )
  {
    // 分别为属性赋值
    this.name = name;  //super.name = name;
    this.age = age;   //super.age = age;
    this.school = school;
  }
  // 此处覆写Person中的talk()方法
  public String talk( )
  {
    return super.talk()+ ", I am from " + this.school ;
  }
}
public class Override2
{
  public static void main( String[] args )
  {
    Student s = new Student( "Jack ", 25, "HAUT" );
    // 此时调用的是子类中的talk()方法
    System.out.println( s.talk() );
  }
}