拼接：

NSArray?*pathArray?=?[NSArray?arrayWithObjects:@"here", ?@"be",?@"dragons",?nil]; ?

NSLog(@"%@",[pathArray?componentsJoinedByString:@"?"]);

分割：

NSString*?str?=?@"here?be?dragons";??

[str?componentsSeparatedByString:@"?"];??

for(NSString*?s?in?str)?NSLog(s);

去空格:

NSString

*number_temp = [number stringByReplacingOccurrencesOfString:@" " withString:@""];

轉UTF-8:

NSString *bb = [s?stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];