this关键字的理解

public class Teacher {
String name;
String subject;
int age;


public Teacher() {
    
}
public Teacher(String name,String subject,int age) {
this.name=name;
this.subject=subject;
this.age=age;
System.out.println(this.name);
}
public void teach(){
    System.out.println(name+"正在讲"+subject);
}
    
}







public class Test{
    public static void main(String[] args) {
Teacher s=new Teacher("老子","四书五经",8);
s.teach();
Teacher s1=new Teacher("墨子","haha",52);    
s.teach();



}
}