StringBuilder的添加和反转方法

• public StringBuilder append(任意类型) //添加数据，并返回对象本身
• public StringBuilder reverse() //返回相反的字符序列

代码演示：

package test;
public class Main {
    public static void main(String[] args) {
        StringBuilder s = new StringBuilder();
        StringBuilder s1 = s.append("WTY");//添加对象，并返回对象本身
        System.out.println("s:" + s);
        System.out.println("s1:" + s1);
        System.out.println(s == s1); // s和s1其实是同一个对象
        System.out.println("--------");
        s1 = s.append(19);
        System.out.println("s:" + s);
        System.out.println("s1:" + s1);
        System.out.println(s == s1);
        System.out.println("--------");
        StringBuilder s2 = new StringBuilder();
        s2.append("WTY").append(19);//链式编程法
        System.out.println("s2:" + s2);
        System.out.println("--------");
        //反转
        s2.reverse();
        System.out.println("s2:" + s2);
    }
}

运行结果：