使用NSString 去掉前后空格或回车符

想要去掉字符串的前后空格和回车符，很简单，如下：

NSString *string = @" spaces in front and at the end ";
NSString *trimmedString = [string stringByTrimmingCharactersInSet:
[NSCharacterSet whitespaceAndNewlineCharacterSet]]; 
NSLog(trimmedString);