nsdictionary

for each loop in Objective-C for accessing NSMutable dictionary

由 不打扰是莪最后的温柔 提交于 2019-11-26 11:45:46
问题 I am finding some difficulty in accessing mutable dictionary keys and values in Objective-C. Suppose I have this: NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init]; I can set keys and values. Now, I just want to access each key and value, but I don\'t know the number of keys set. In PHP it is very easy, something as follows: foreach ($xyz as $key => $value) How is it possible in Objective-C? 回答1: for (NSString* key in xyz) { id value = xyz[key]; // do stuff } This works for every

Serialize and Deserialize Objective-C objects into JSON

由 眉间皱痕 提交于 2019-11-26 10:35:43
问题 I need to serialize and deserialize objective-c objects into JSON to store in CouchDB. Do people have any example code for best practice for a general solution? I looked at a few JSON framework and they are stopped at the NSDictionary/NSArray level. i.e. A lot of framework will serialize and deserialize NSDictionary/NSArray into JSON. But I still have to do the work to convert NSDictionary into Objective-C objects. To make things more complex, my Object A can have reference to an NSArray

Replace all NSNull objects in an NSDictionary

由 徘徊边缘 提交于 2019-11-26 10:29:39
问题 I\'m curious, I currently have an NSDictionary where some values are set to an NSNull object thanks to the help of json-framework. The aim is to strip all NSNull values and replace it with an empty string. I\'m sure someone has done this somewhere? No doubt it is probably a four liner and is simple, I am just far too burnt out to figure this out on my own. Thanks! 回答1: Really simple: @interface NSDictionary (JRAdditions) - (NSDictionary *)dictionaryByReplacingNullsWithStrings; @end

将Array、Dictionary等集合类的序列化和反序列化

由 牧云@^-^@ 提交于 2019-11-26 10:15:45
来自：http://blog.prosight.me/index.php/tag/writetofile Objective-C的集合类序列化到文件中或者从文件中反序列化其实很简单，请看下面的示例 代码： NSArray *array = [ NSArray arrayWithObjects: @ "Hefeweizen" , @ "IPA" , @ "Pilsner" , @ "Stout" , nil ] ; NSDictionary *dictionary = [ NSDictionary dictionaryWithObjectsAndKeys: array, @ "array" , @ "Stout" , @ "dark" , @ "Hefeweizen" , @ "wheat" , @ "IPA" , @ "hoppy" , nil ] ; // 得到documents directory的路径 NSArray *paths = NSSearchPathForDirectoriesInDomains ( NSDocumentDirectory, NSUserDomainMask, YES ) ; if ( [ paths count ] > 0 ) { // Array的保存路径 NSString *arrayPath = [ [ paths objectAtIndex

Sorting NSArray of dictionaries by value of a key in the dictionaries

由 本秂侑毒 提交于 2019-11-26 08:53:32
问题 I have an array populated by dictionaries, and I need to sort the array alphabetically by the values of one of the keys of the dictionaries. This is my array: tu dictus: ( { brand = Ryul; productTitle = Any; quantity = 1; subBrand = \"Ryul INJ\"; type = Product; }, { brand = Trol; productTitle = Different; quantity = 2; subBrand = \"\"; type = Brand; }, { brand = Dtor; productTitle = Any; quantity = 1; subBrand = \"\"; type = Product; }, { brand = Ryul; productTitle = Different; quantity = 2;

Getting NSDictionary keys sorted by their respective values

由 感情迁移 提交于 2019-11-26 07:28:20
问题 I have an NSMutableDictionary with integer values, and I\'d like to get an array of the keys, sorted ascending by their respective values. For example, with this dictionary: mutableDict = { \"A\" = 2, \"B\" = 4, \"C\" = 3, \"D\" = 1, } I\'d like to end up with the array [\"D\", \"A\", \"C\", \"B\"] . My real dictionary is much larger than just four items, of course. 回答1: The NSDictionary Method keysSortedByValueUsingComparator: should do the trick. You just need a method returning an

How can I sort an NSArray containing NSDictionaries?

由 非 Y 不嫁゛ 提交于 2019-11-26 06:48:04
问题 I have an NSArray which contains NSDictionary objects. Each of these NSDictionary objects contains an ORDER key. How can I sort this NSArray based on this key within each of these NSDictionaries ? 回答1: Here is an example. Imagines you have an array of dictionnaries. Ecah dictionnary have 2 keys "name" & "dateOfBirth". You can sort your array by "name" like this : // // Sort array by name // NSSortDescriptor *Sorter = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; [myArray

how to do true deep copy for NSArray and NSDictionary with have nested arrays/dictionary?

由 こ雲淡風輕ζ 提交于 2019-11-26 06:33:45
问题 Question: Is there a way to use existing objective-c methods to do a full deep copy of a NSDictionary or NSArray, that themselves have nested dictionaries or arrays within them? That is I have read the problem may be when it hits a nested dictionary or array it only copies the pointer to the nested item, and not copy the item truely. Background: So as an example for me I\'m trying to load/save the following config with NSUserDefaults and when loading need to convert the immutable copies one

How can we store into an NSDictionary? What is the difference between NSDictionary and NSMutableDictionary?

由 纵饮孤独 提交于 2019-11-26 06:15:39
问题 I am developing an application in which I want to use an NSDictionary . Can anyone please send me a sample code explaining the procedure how to use an NSDictionary to store Data with a perfect example? 回答1: The NSDictionary and NSMutableDictionary docs are probably your best bet. They even have some great examples on how to do various things, like... ...create an NSDictionary NSArray *keys = [NSArray arrayWithObjects:@"key1", @"key2", nil]; NSArray *objects = [NSArray arrayWithObjects:@

Convert JSON feed to NSDictionary

由 流过昼夜 提交于 2019-11-26 05:29:53
问题 Where JSON_CATEGORY_DATA_URL_STRING is my feed URL, which returns fine as: [ { \"group\":\"For Sale\", \"code\":\"SSSS\" }, { \"group\":\"For Sale\", \"category\":\"Wanted\", \"code\":\"SWNT\" } ] I cannot seem to get a nice NSDictionary (or NSArray ) out of the following code: + (NSDictionary *)downloadJSON { NSDictionary *json_string; NSString *dataURL = [NSString stringWithFormat:@\"%@\", JSON_CATEGORY_DATA_URL_STRING]; NSLog(@\"%@\",dataURL); NSURLRequest *request = [NSURLRequest
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