Java继承——Object_java object继承于谁

一、Object类

• java中，所有类都直接或间接继承自java.lang.Object类，可以说Object是java中所有类的祖先即根类
• java中任何类都继承了Object类中的方法，主要有
  toStrring()

public String toString() {
    // TODO Auto-generated method stub
	//return super.toString();					//默认打印包名+类内存地址
	return "person meaage:" + name + address;	//方法重写
}

System.out.println(s.toString());
/*
person meaage:xiaowei甲3214
*/
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equals()

public boolean equals(Object arg0) {
	// TODO Auto-generated method stub
	//return super.equals(arg0);       //默认比较的是地址
	Person s = (Person)arg0;			//强转
	if(this.address == s.address && this.name == s.name){//比较成员变量
		return true;
	}else{
		return false;
	}
}

System.out.println(s.equals(s2));
/*
true
*/
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hashcode()
clone()
getClass()
finalize()

二、代码演示

class Person{//class 相当于c语言的struct
	String name;
    String address;
	
	public void printInfo(){
		System.out.println("name=" + name);
	}
	
	private void printAddr(){
		System.out.println("address=" + address);
	}
	
	public String toString() {
		// TODO Auto-generated method stub
		//return super.toString();					//默认打印包名+类内存地址
		return "person meaage:" + name + address;	//方法重写
	}
	
	public boolean equals(Object arg0) {
		// TODO Auto-generated method stub
		//return super.equals(arg0);       //默认比较的是地址
		Person s = (Person)arg0;			//强转
		if(this.address == s.address && this.name == s.name){//比较成员变量
			return true;
		}else{
			return false;
		}
	}
}

public class Test {
	public static void main(String[] args) {	
		Person s = new Person();
		s.name = "xiaowei";
		s.address = "甲3214";
		
		Person s2 = new Person();
		s2.name = "xiaowei";
		s2.address = "甲3214";
		
		System.out.println(s.equals(s2));
		System.out.println(s.toString());
	}
}


/*
true
person meaage:xiaowei甲3214
*/
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师承上官可编程 —— 陈立臣