java 类继承

//父类
package SeeClass;

public class Compare {
	String name;
	int age;   //实例变量,不可以被类访问，但可以用实例
	static String hobby ="eat";  // 带static 类变量，类变量可以被classname.var形式访问，也可以instance。var
	private String drink = "water";
	public Compare(String name,int age) {
		this.name=name;
		this.age=age;
	}
	
	public String  getstring() {
		return this.name;
	}
	public static void main (String [] args) {
		Compare compare =new Compare("zs",21);
	}
}

// 子类

package SeeClass;

class UseCompare extends Compare{
  String user;
  public UseCompare(String user,String name,int age) {
	 //先继承父类
	super(name,age);
	//重构父类参数
	this.user=user;
//	this.name=name;
//	this.age=age;
  }
  // 重写父类get string方法
  public String getstring() {
	  return this.user;
  }
public static void main(String [] args) {
	
	UseCompare test = new UseCompare("admin","test",22);
	Compare compare =new Compare("zs",21);
	System.out.println(test.age);  //子类实例访问实例变量
	System.out.println(compare.name);  // 父类实例访问实例变量
	System.out.println(Compare.hobby); // 父类访问类变量
	System.out.println(UseCompare.hobby); //子类访问类变量
//	System.out.println(Compare.age);  //这个报错为啥,因为private 私有的子类你也无权访问
}
}