package string;import java.lang.StringBuilder;public class test2 {?? ??? ???? public static void main(String[] args) {?? ??? ??? ?// 創(chuàng)建一個(gè)空的StringBuilder對(duì)象?? ??? ??? ?StringBuilder str=new StringBuilder();?? ??????? ??? ??? ??? ?// 追加字符串?? ??? ??? ?str.append("jaewkjldfxmopzdm");?? ??? ??? ??? ??? ?int i=str.length();?? ??? ?? ?? ???????? // 從后往前每隔三位插入逗號(hào)?? ???????? while(i>0){?? ???????????? i=i-3;?? ? ??? ??? ??? ?str.insert(i,',');?? ??????? ??? ???????? }?? ??? ??? ??? ???????? // 將StringBuilder對(duì)象轉(zhuǎn)換為String對(duì)象并輸出?? ??? ??? ?System.out.print(str.toString());?? ??? ?}?? ?}