for-in-loop

I found this answer: https://stackoverflow.com/a/5163334/1364174 Which presents how for in loop is implemented. NSFastEnumerationState __enumState = {0}; id __objects[MAX_STACKBUFF_SIZE]; NSUInteger __count; while ((__count = [myArray countByEnumeratingWithState:&__enumState objects:__objects count:MAX_STACKBUFF_SIZE]) > 0) { for (NSUInteger i = 0; i < __count; i++) { id obj = __objects[i]; [obj doSomething]; } } The problem is that, I found it wrong. First of all, when you have Automatic Reference Counting (ARC) turned on, you got an error Sending '__strong id *' to parameter of type '_

I'm communicating with an API that sends back an NSDictionary as a response with data my app needs (the data is basically a feed). This data is sorted by newest to oldest, with the newest items at the front of the NSDictionary. When I fast enumerate through them with for (NSString *key in articles) { ... } the order is seemingly random, and thus the order I operate on them isn't in order from newest to oldest, like I want it to be, but completely random instead. I've read up, and when using fast enumeration with NSDictionary it is not guaranteed to iterate in order through the array. However,

I guess the preferred way of looping through an object is this: for (var prop in obj) { if( obj.hasOwnProperty( prop ) ) { console.log("obj." + prop + " = " + obj[prop]); } } MDN says that Deleted, added or modified properties A for...in loop iterates over the properties of an object in an arbitrary order (see the delete operator for more on why one cannot depend on the seeming orderliness of iteration, at least in a cross-browser setting). So if I don't modify object properties during iteration I can be guaranteed the correct order i.e. the order in which keys/properties appear in an object

I'm working on a JS to show different messages depending on the current url's hash. Now, that's all working, but I was wondering what the best way would be to access my messages (They'll be coded into a .js file) At the moment, I have the messages stored in a object like this: popups = { TemplateMessage: { title: "Template Popup Title", message: "This is a template popup message! Copy this to add a message.", modal: true }, AnotherMessage: { title: "another title", message: "message.", modal: true } /* etc */ }; the way I'm accessing these messages is with a "for in: loop, as follows: for (key

I have seen answers here which explain how to tell the compiler that an array is of a certain type in a loop. However, does Swift give a way so that the loop only loops over items of the specified type in the array rather than crashing or not executing the loop at all? Martin R You can use a for-loop with a case-pattern: for case let item as YourType in array { // `item` has the type `YourType` here // ... } This will execute the loop body only for those items in the array which are of the type (or can be cast to) YourType . Example (from Loop through subview to check for empty UITextField -

What is the difference between for..in and for each..in statements in javascript? Are there subtle difference that I don't know of or is it the same and every browser has a different name for it? Brian R. Bondy "for each...in" iterates a specified variable over all values of the specified object's properties. Example: var sum = 0; var obj = {prop1: 5, prop2: 13, prop3: 8}; for each (var item in obj) { sum += item; } print(sum); // prints "26", which is 5+13+8 Source "for...in" iterates a specified variable over all properties of an object, in arbitrary order. Example: function show_props(obj,

I have this for-in loop: for button in view.subviews { } Now I want button to be cast into a custom class so I can use its properties. I tried this: for button in view.subviews as AClass But it doesnt work and gives me an error: 'AClass' does not conform to protocol 'SequenceType' And I tried this: for button:AClass in view.subviews But neither does that work. For Swift 2 and later: Swift 2 adds case patterns to for loops, which makes it even easier and safer to type cast in a for loop: for case let button as AClass in view.subviews { // do something with button } Why is this better than what