Solved

dot syntax works but square bracket syntax doesn't

Posted on 2014-03-01
3
225 Views
Last Modified: 2014-03-02
hey guys,

i'm trying to write this line of code and dot syntax works but not square brackets - which perplexes me.

@property(weak,nonatomic)IBOutlet UITextView *tView; //defined in header file

[[self tView] text]=@""; //doesn't work - expression not assignable (in implementation file)
self.tView.text=@""; //this works (in implementation file)

i'm using Xcod 5.0.2
0
Comment
Question by:developingprogrammer
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 12

Accepted Solution

by:
satsumo earned 500 total points
ID: 39898495
The square brackets don't work because text is a get method. It returns a pointer to the NSString object that is the text property. To set the text property with square bracket syntax you would use:

[[self tlView] setText: @""];
The compiler converts dot syntax to either get or set method according to the context, which is why it works. This question should really be in an Objective-C topic but I can't find one.
0
 

Author Comment

by:developingprogrammer
ID: 39898510
whao satsumo, that is definitely very enlightening for me. i definitely didn't know that about . syntax and square brackets syntax. but then again i am almost completely new. thanks so much for letting me know though! = )

yup i agree with you that this question should definitely be in Objective C topic but there isn't one and in fact i've raised a question about this which Kent has answered (http://www.experts-exchange.com/Programming/Languages/C/Q_28377590.html). here is the link. i'm hoping that perhaps Objective C can be added as a topic and EE would be enriched = )

thanks once again! = )
0
 
LVL 12

Expert Comment

by:satsumo
ID: 39898541
If you're new to Obj-C I very much recommend this book:

http://www.amazon.co.uk/Objective-C-Pocket-Reference-Andrew-Duncan/dp/0596004230

It covers pretty much everything in a straightforward way and it doesn't cost much. It sits on my desk permanently now, so that I can look up those odd bits of syntax. It doesn't cover iOS and its not a 'how to program' guide, but I doubt you need anything like that.
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Windows programmers of the C/C++ variety, how many of you realise that since Window 9x Microsoft has been lying to you about what constitutes Unicode (http://en.wikipedia.org/wiki/Unicode)? They will have you believe that Unicode requires you to use…
This is a short and sweet, but (hopefully) to the point article. There seems to be some fundamental misunderstanding about the function prototype for the "main" function in C and C++, more specifically what type this function should return. I see so…
The goal of this video is to provide viewers with basic examples to understand how to use strings and some functions related to them in the C programming language.
The goal of this video is to provide viewers with basic examples to understand opening and reading files in the C programming language.

695 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question