1、成员变量练习

package lianxiti;

public class Book {
                                   //zai 该类中定义并使用变量
    private int id;
    private String name;
    private String category;
    public String getName(){
        
        int id=0;
        
        setName("Java");
        
        return id+this.name;
    }
    private void setName(String name){
        
        this.name=name;
    }
    public Book getBook(){
        
        return this;
    
    }
}