test.java

来自「JAVA培训用实用代码」· Java 代码 · 共 24 行

public class Test{
	public static void main(String args[]){
		Person p = new Student();
		Object o = new Person();
		o = new String("hi");	
	}
}

class Person {
	protected String name;
	protected int age;
	public String getInfo() {
	   	return "Name: "+ name + "\n" +"age: "+ age;
	}
}

class Student extends Person {
	protected String school;
	public String getInfo() {
  	   	return  "name: "+ name + "\nage: "+ age 
	          + "\nschool: "+ school;
	}
}