如何去掉字符串的空格/换行/回车

NSString *str = @"你好,这句话有空格,就在这 ,\n还有一个回车 ";

NSLog(@"%@",str);

str = [str stringByReplacingOccurrencesOfString:@"\r" withString:@""];

str = [str stringByReplacingOccurrencesOfString:@"\n" withString:@""];

str = [str stringByReplacingOccurrencesOfString:@" " withString:@""];

NSLog(@"%@",str);