JAVA基础学习之路this关键字

Posted 2020-11-11 1996

class Book {
    String name;
    int price;
    int num;
//构造方法之间的互相调用解决了代码的重复问题，但是一定要留出口
    public Book() {
        this("请输入书名",0,0);
    }
    public Book(String name) {
        this(name,9999,9999);//this调用方法
    }
    public Book(String name,int num) {
        this(name,num,9999);
    }
    public Book(String name,int num,int price) {
        this.name = name; //this调用属性
        this.price = price;
        this.num = num;
        
    }
    public String getInfo() {
        return "书名: "+this.name+"\n"+
                "数目: "+this.num+"\n" +
                "单价: " +this.price;
        
    }
} 

public class test1 {
    public static void main(String args[]) {
        Book book_0 =  new Book();
        Book book_1 =  new Book("我的世界");
        Book book_2 =  new Book("老人与海",5);
        Book book_3 =  new Book("陆炳勋",3,2);
        System.out.println(book_0.getInfo());
        System.out.println(book_1.getInfo());
        System.out.println(book_2.getInfo());
        System.out.println(book_3.getInfo());
    }    
}