StringBuffer类

String是不可变字符序列，StringBuffer是可变字符序列。

区别：修改字符串对象时，StringBuffer的效率更高。

public class Test{public static void main (String[] args){String s = "Mircosoft";char[] a = {'a','b','c'};StringBuffer s1 = new StringBuffer(s);s1.append('/').append("IBM").append('/').append("Sun");System.out.println(s1);StringBuffer s2 =new StringBuffer("数字");for(int i=0;i<=9;i++){s2.append(i);}System.out.println(s2);s2.delete(8,s2.length()).insert(0,a);System.out.println(s2);System.out.println(s2.reverse());}}