成员变量声明和初始化

package lianxii;

public class Book {

    private String title;

    public void setTitle(String title1) {

        title = title1;
    }

    public String getTitle() {

        return title;
    }

    public static void main(String[] args) {

        Book b = new Book();
        b.setTitle("titlejuiiuuu");//调用上面setTitle方法
        String s = b.getTitle();//调用上面getTitle方法
        String t = s.toLowerCase();
        String u = s.toUpperCase();
        System.out.println(s);
        System.out.println(t);
        System.out.println(u);
    }
}