去除掉首尾的空白字符和换行字符

NSString* headerData = @"    this     is a    test    .   "; 

 //去除掉首尾的空白字符和换行字符

headerData = [headerData stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; 

headerData = [headerData stringByReplacingOccurrencesOfString:@"/r" withString:@""];

 headerData = [headerData stringByReplacingOccurrencesOfString:@"/n" withString:@""];