If you retrieve an instance variable within a static method based on a parameter supplied to the static method, is it possible the instance variable can get stepped on if the static method is called at exactly the same time by different callers? The method I am calling is defined below and I am wondering if the instance variable invoice ...
In my iPhone apps I regularly do this in xCode v3.2.3: Declare a BOOL variable in the *.h file Use @property in the same *.h file. Use @sythesize in the matching *.m file. I accidentally forgot to do #1... but it still complied fine. 0 warnings. 0 errors. 0 analyzer errors. How can that be? Shouldn't my code to loaded with compil...
I'm doing this in the context of Android, but my problem is understanding Java. I'm somewhat new to both, so hopefully I'm using the correct terminology here. I've got a number of sub-classes inheriting/extending from my super class (an Android Activity extension) called SuperActivity. I've also defined another class type called Netwo...
Heres some sample code, class Base { private int val; Base() { val = lookup(); } public int lookup() { //Perform some lookup // int num = someLookup(); return 5; } public int value() { return val; } } class Derived extends Base { private int num = 10; public int lookup() { return num; } } clas...
From example: local_var = "Thanks!" @instance_var = "Thank you ,too" Then how can I get the local_var and instance_var part by them self. I mean weather there is a method maybe called get_self_name to get the name of himself: local_var.get_self_name # => 'local_var' @instance_var.get_self_name # => '@instance_var' or => 'instance_var...
Hey guys, A JavaScript newbie here. I have this following code: function testObject(elem) { this.test = "hi"; this.val = elem; console.log(this.test+this.val); echo(); function echo () { console.log(this.test+this.val); } } var obj = new testObject("hello"); When it is run, I expect "hihello" to be ...
I've been running into this problem many times and I never bothered to learn why its happening and learn what "static" actually means. I just applied the change that Eclipse suggested and moved on. public class Member { // Global Variables int iNumVertices; int iNumEdges; public static void main(String[] args) { // do stuff ...
Suppose in Ruby on Rails, there is a return of JSON data: render :json => array_of_purchases and this array_of_purchases contains many Purchase objects, each one with a product_id. Now if we want to add a property to the JSON returned, so that each Purchase object will also include its Product object data: "product": { "id": 123, "n...
Here is the class which gives me a modal view of the camera @interface ViewController : UIViewController <UIImagePickerControllerDelegate> { UIImagePickerController *cameraView; // camera modal view BOOL isCameraLoaded; } @property (nonatomic, retain) UIImagePickerController *cameraView; - (IBAction)cameraViewbuttonPressed; - (voi...
I want to declare a c array as an instance variable (e.g. int arr[256]) in the interface block of a Cocoa object. I know that @property doesn't support c arrays but how to manually add the getter and setter for the c array and where should I alloc and release it? Any input will be appreciated. I really don't want to use NSMutableArray f...
I've come across Objective-C code that declares a variable right below the @implementation line in a .m file and not in the @interface block of the .h file. It then proceeds to use it like a private ivar. I haven't been able to find documentation about declaring variables this way and would like to know the impact. Example: .h @in...
Hi all, First off, I want to say this site is AWESOME! and it helped me do lots of stuff while creating my iPhone app. Now, my problem is: When I launch my app, I have a UIImageView that loads an image depending on an if/else statements in -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event method. These images are assig...
Scenario 1: For a UIViewController, is it better to (1) create an ivar for a UIView that I access again in 1 or 2 functions outside of loadView? Or, (2) should I just tag it in loadView and then use - (UIView *)viewWithTag:(NSInteger)tag to access it again in the other functions? I'm guessing that option 1 increases the memory by the siz...
I always see example code where in the viewDidLoad method, instead of saying, for example someInstanceVar = [[Classname alloc] init]; they always go Classname *tempVar = [[Classname alloc] init]; someInstanceVar = tempVar; [tempVar release]; Why is this? Isn't it the exact same thing, just longer? ...
Hi, I tried to understand the three20 ttnavigator example code, and in the MenuController.h file, it is as follows: typedef enum { MenuPageNone, MenuPageBreakfast, MenuPageLunch, MenuPageDinner, MenuPageDessert, MenuPageAbout, } MenuPage; @interface MenuController : TTTableViewController { MenuPage _page; } @property(non...
I have an app that heavily relies on dates. There is a moderately expensive calculation that is needed to set these dates, based on the current date. As far as each request is concerned, these dates are constants -- they don't change once created -- but they do change throughout the week. The dates are used in both controllers and models...
A problem happens when I was trying to release one of my instance variables and reassign it a new value. I would like to release the address that a instance variable points to, and re-assign a new value to it. The code look like this: The .h @interface MapPageController : UIViewController<MKMapViewDelegate> { AddressAnnotationManager...
I was wondering if there is a shorter, better or cleaner way to assign and use class variables in PHP, then through $this->instance_variable ? class Bar { # internal variables var $foo = "Hello World"; public function foo() { return $this->foo; } } I am not very familiar with all PHP's variable scoping, but from what I u...
I'm trying to create a set of instances that have different instance names using instance_variable_set to change the instance name and I can't seem to get it to work. for i in 0..3 do username_str = String.new username_str = 'user_' + i.to_s username_new = User.new username_new.instance_variable_set("@#{WHAT_DO_I_PUT...
Consider the code below: <?php class Base { protected $name = "Base"; public function getName() { return $this->name; } } class Foo extends Base { protected $name = "Foo"; } $f = new Foo(); echo $f->getName(); // output: Foo $b = new Base(); echo $b->getName(); // output: Base Since in ...