在objective－c中去掉字符串前后空格的方法（类似于C＃中的trim方法）如下：

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