StringBuilder和StringBuffer的用法

package com.sanyuan.WraperClassTest;

/**
 * StringBuilder和StringBuffer的用法
 * @author huang
 *
 */

public class TestString {
    public static void main(String[] args) {
        String str = "aabb";   //不可变字符序列
        StringBuilder sb = null;  //可变字符序列，线程不安全，效率高
        StringBuffer sb2 = null;  //可变字符序列，线程安全，效率低
        
        sb = new StringBuilder("gao");
        sb.append(123);
        sb.append(456);
        System.out.println(sb);
        sb.append("aa").append("bb").append("cc");
        System.out.println(sb);
        
        for (int i = 0; i < 10; i++) {
            sb.append(i);
        }
        System.out.println(sb);
        
        /*StringBuffer，下面的方法同样使用与StringBuild*/
        sb2 = new StringBuffer("高中的你");
        sb2.insert(0, "爱").insert(0, "我"); //插入字符串
        System.out.println(sb2);
        sb2.delete(0, 2); //删除字符串
        System.out.println(sb2);
        sb2.deleteCharAt(0).deleteCharAt(0);  //删除某个字符
        System.out.println(sb2.charAt(0));  //获取某个字符
        System.out.println(sb2.reverse());  //字符串逆序
        
    }

}