1.将array数组转换为string字符串
NSString *str = [array componentsJoinedByString:@"#"];//#为分隔符
输入：[str,kkk,jjj]
输出：str#kkk#jjj
2.将string字符串拆分为array数组[有分割符]
NSArray *array = [str componentsSeparatedByString:@"#"];//#为分隔符
输入: str#kkk#jjj
输出: [str,kkk,jjj]