Javathis关键字的引用详解

public class Date {
    public int year;
    public int month;
    public int day;
    
    public void setDay(int y,int m,int d){
        year = y;
        month = m;
        day = d;
    }
    
    public void printDate(){
        System.out.println(year + "/" + month + "/" + day);
    }
    public static void main(String[] args){
        //构造三个日期类型的对象
        Date d1 = new Date();
        Date d2 = new Date();
        Date d3 = new Date();
       
        //对d1,d2,d3的日期进行设置
        d1.setDay(2022,3,25);
        d2.setDay(2022,3,26);
        d3.setDay(2022,3,27);
        
        //打印日期中的内容
        d1.printlnDate();
        d2.printlnDate();
        d3.printlnDate();
        
    }
}

public void setDay(int year,int month,int day){
    year = year;
    month = month;
    day = day;
}

public class Date {
    public int year;
    public int month;
    public int day;
    
    public void setDay(int year,int month,int day){
        this.year = year;
        this.month = month;
        this.day = day;
    }
    public void printDate(){
        System.out.println(this.year+"/"+this.month+"/"+this.day);
    }
    
}

public static void main(String[] args) {
        Date d = new Date();
        d.setDay(2020,9,15);
        d.printDate();
    }