Hello, I have been developing with objective C and the Cocoa framework for quite some time now. However it is still not absolutely clear to me, when am I supposed to set object references to nil. I know it is recommended to do so right before releasing an object that has a delegate and you should also do so in the viewDidUnload method f...
I expect to see a nil returned with the following embedded Ruby: <%=h [@inventory.origin.code] %> it returns a "NoMethodError nil object". However when an object is in fact present, it functions just fine (as expected). Therefore I created this test (following this advice): <b>origin_id:</b> <% if (@inventory.origin.code.nil? or @...
Hey stackfolk, I'm working in the IPhone SDK, and am pretty new to objective-c. Right now I'm working with NSUserDefaults to save and restore setting on my IPhone app. In order to save the classes that have been created, I encode them into dictionary form, and then save the NSdictionary. My problem is that I can't find a reasonable w...
I know this is probably rather trivial but i have had a lookt at previous questions and i've tried them but they still issued an error unfortunately :s My issue is the following, i have an html.erb file and i want a certain body text to be display given a condition or another if it is false i have <% if [email protected] do %> more cod...
in a previous question i asked how to split an array into two equal pieces in ruby on rails. this is how i did it: >> a = [1,2,3,4,5] => [1, 2, 3, 4, 5] >> a.in_groups_of( (a.size/2.0).ceil ) if a.size > 0 => [[1, 2, 3], [4, 5, nil]] now i've got a nested array that contains nil elements if the size of the array is odd. how can i remo...
Currently I understand it as a kind of "empty object". But what's it really? ...
My application needs to deal with arrays of fixed size. The problem is that sometimes elements are nil but nil is a forbidden value. I think an easy way is to replace nil values with an the closest non-nil value (right before or right after). The nil values can be first, last or even multiples. Here are some examples of what I'm looking...
I want to draw nil instead of the colors, because in the end I want the code to erase a section of the UIImageView in order that you can see what is behind the UIImageView. - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; CGPoint currentPoint = [touch locationInView:self.v...
how do i check if a BOOL is set in objective-c (iphone)? i know that it can be done with an int or float this way: NSNumber *Num = [prefs floatForKey:@"key"]; for example ...
I'm curious why a variable overtly assigned to nil, prints as (null) with NSLog: NSString *myVar = nil; NSLog(@"%@", myVar); # RESULT: ' (null) ' This is of course quite confusing given all the different kinds of "nothingness" to figure out in Objective-C, and had me trying to test various IF NULL syntaxes. ...
I have the following UITableView DataSource method: - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index On some items (i.e. section index titles) I just want to return "nothing", so that the table view won't jump to any section. I tried to return nil, but I get the "R...
NSArray *array = [[NSArray alloc] initWithObjects:@"ΕΛΤΑ", @"ΕΛΤΑ COURIER", @"ACS", @"ACS ΕΞΩΤΕΡΙΚΟ", @"DHL", @"INTERATTICA", @"SPEEDEX", @"UPS", @"ΓΕΝΙΚΗ ΤΑΧΥΔΡΟΜΙΚΗ", @"ΜΕΤΑΦΟΡΙΚΕΣ ΕΞΩΤΕΡΙΚΟΥ", nil]; This is working because it has nil at the end. But I add objects l...
Hello, I don't know how to handle nils my sort function gets. When I have this checking in it, table.sort crashes after some calls. if a == nil then return false elseif b == nil then return true end With this error:invalid order function for sorting. But according to the documenatiton, sort function should return false, if a ...
Hi, I have a Core Data model with 2 entities: Game and ScoreTable. A Game has an optional relationship with ScoreTable. I usually check if a game has a ScoreTable by doing: NSManagedObject *scoreTable = [myGame valueForKey: @"scoreTable"]; if (scoreTable == nil) { // wtv } And when I want to delete a ScoreTable from a Game I'll j...
I have created a site which utilizes subdomains and searches whether or not the user is at: subdomain.domain.com or domain.com. If the user is in subdomain.domain.com, /views/layouts/application.html.erb appears, if the user is in domain.com /views/layouts/promo_site.html.erb appears. To accomplish this I closely followed Robby on Rails ...
I have a method that returns a hash, or nil: def person_of_age(age) some_hash = @array_of_hashes.select { |h| h.age == age }.last return some_hash end I want to use this hash like so: my_height = 170 my_age = 30 if my_height < self.person_of_age(my_age)['height'] puts "You are shorter than another person I know of the same age!"...
Hi! Allknowing that in lisp list must contain nil, but expression like (print (cons 1 (cons 3 2))) dont throw any errors and prints (1 3 . 2) Is it correct? I use GNU Clisp. Help me please ...
SO I wish to check to see if the item in my array [clientDataArray objectForKey:@"ClientCompany"] is nil. temp = [clientDataArray objectForKey:@"ClientCompany"]; if (temp != [NSNull null]) infofieldCompany.text = temp; So far I have been able to achieve this through the above code, but it does give me the warnings warning: '...
Actually my question here is: are null and nil equivalent or not? I have an example but I am confused when they are equal when they are not. NSNull *nullValue = [NSNull null]; NSArray *arrayWithNull = [NSArray arrayWithObject:nullValue]; NSLog(@"arrayWithNull: %@", arrayWithNull); id aValue = [arrayWithNull objectAtIndex:0]; if (aValu...
What's the effect in Ruby when you pass nil to the constructor as in: s = String(nil) or a = Array(nil) Does this mean that s or a is nil or that s or a is an unpopulated object of type String or type Array? ...