简单的继承，方法重载与方法覆盖

[java]代码库

package com.jiarui;

public class Demo1 {

	public static void main(String[] args) {
		
		Dog dog1= new Dog(2,"大黄");
		System.out.println(dog1.name+"的年龄为："+dog1.getAge());
		dog1.Cry();
		
		Cat cat1=new Cat(3,"小花");
		cat1.Cry();
		System.out.println(cat1.name+"的年龄为："+cat1.getAge());
		
		Abc abc= new Abc();
		System.out.println(abc.getNum(12,18));

	}

}

class Animal{
    int age;
	String name;
	
	public Animal(){
		
		this.age=age;
		this.name=name;
	}
	
	public void Cry(){
		System.out.println("动物的叫声是：不知道。");
	}
}

class Dog extends Animal{
	//private int age;
	//public String name;
	
	public Dog(int age,String name){
		
		this.age=age;
		this.name=name;
	}
	
	//方法的覆盖
	public void Cry(){
		
		System.out.println("狗的叫声是：汪汪");
	}
	
	public int getAge(){
		
		return this.age;
	}
	
}

class Cat extends Animal{
	
	public Cat(int age,String name){
		
		this.age=age;
		this.name=name;
	}
	
	public void Cry(){
		System.out.println("猫的叫声是：喵喵!");
	}
	
	public int getAge(){
		
		return this.age;
	}
}

class Abc{
	
	public int getNum(int i,int j){
		
		if (i>j) {
			
			return i;
		}else {
			
			return j;
		}
	}
	//方法重载：只是返回类型不一样，不能构成重载
	public float getNum(float a,float b){
		
		if (a>b) {
			
			return a;
			
		}else {
			return b;
		}
	}
	
	
}