NSString *string = @"How are you";
NSLog(@"uppercaseString:%@", string.uppercaseString); //全部大寫
NSLog(@"lowercaseString:%@", string.lowercaseString); //全部小寫
NSLog(@"capitalizedString:%@", string.capitalizedString); //首字母大寫
打印數據:
uppercaseString:HOW ARE YOU
lowercaseString:how are you
capitalizedString:How Are You