    NSDictionary* fileAttributes = 
        [[NSFileManager defaultManager] attributesOfItemAtPath:filename 
                                                         error:nil]

From the file attribute keys, you can get the date, size, etc. But how do you get the duration?

How to get the duration of an audio file in iOS?

Is there a way to store a selector in an `NSDictionary`, without storing it as an `NSString`?

Store selector as value in an NSDictionary

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&#39;t know the number of keys set.

In PHP it is very easy, something as follows:

    foreach ($xyz as $key =&gt; $value)

How is it possible in Objective-C?
 

for each loop in Objective-C for accessing NSMutable dictionary

I have a simple Dictionary which is defined like:

    var dict : NSDictionary = [ 1 : &quot;abc&quot;, 2 : &quot;cde&quot;]

Now I want to add an element into this dictionary: `3 : &quot;efg&quot;`

How can I append `3 : &quot;efg&quot;` into this existing dictionary?

How to append elements into a dictionary in Swift?

I know `NSDictionaries` as something where you need a `key` in order to get a `value`. But how can I iterate over all `keys` and `values` in a `NSDictionary`, so that I know what keys there are, and what values there are? I know there is something called a *for-in-loop* in `JavaScript`. Is there something similar in `Objective-C`?

Is there a way to iterate over a dictionary?

I am new to Core Data. I have noticed that collection types are not available as attribute types and would like to know what the most efficient way is of storing array/dictionary type data as an attribute (e.g. the elements that make up an address like street, city, etc. does not require a separate entity and is more conveniently stored as a dictionary/array than separate attributes/fields). Thank you.

Best practice? - Array/Dictionary as a Core Data Entity Attribute

I need to initialize a constant HashMap and would like to do it in one line statement. Avoiding sth like this:

      hashMap.put(&quot;One&quot;, new Integer(1)); // adding value into HashMap
      hashMap.put(&quot;Two&quot;, new Integer(2));      
      hashMap.put(&quot;Three&quot;, new Integer(3));

similar to this in objective C:

    [NSDictionary dictionaryWithObjectsAndKeys:
    @&quot;w&quot;,[NSNumber numberWithInt:1],
    @&quot;K&quot;,[NSNumber numberWithInt:2],
    @&quot;e&quot;,[NSNumber numberWithInt:4],
    @&quot;z&quot;,[NSNumber numberWithInt:5],
    @&quot;l&quot;,[NSNumber numberWithInt:6],
    nil] 

I have not found any example that shows how to do this having looked at so many.
   


adding multiple entries to a HashMap at once in one statement

I am sending `NSString` and `UIImage` using bluetooth. I decided to store both in a `NSDictionary` and then convert the dictionary to `NSData`.

My question is how to convert `NSDictionary` to `NSData` and visa versa?

How can I convert NSDictionary to NSData and vice versa?

I have a JSON string (from PHP&#39;s `json_encode()` that looks like this:

    [{&quot;id&quot;: &quot;1&quot;, &quot;name&quot;:&quot;Aaa&quot;}, {&quot;id&quot;: &quot;2&quot;, &quot;name&quot;:&quot;Bbb&quot;}]

I want to parse this into some sort of data structure for my iPhone app. I guess the best thing for me would be to have an array of dictionaries, so the 0th element in the array is a dictionary with keys `&quot;id&quot; =&gt; &quot;1&quot;` and `&quot;name&quot; =&gt; &quot;Aaa&quot;`. 

I do not understand how the `NSJSONSerialization` stores the data though. Here is my code so far:

    NSError *e = nil;
    NSDictionary *JSON = [NSJSONSerialization 
        JSONObjectWithData: data 
        options: NSJSONReadingMutableContainers 
        error: &amp;e];

This is just something I saw as an example on another website. I have been trying to get a read on the `JSON` object by printing out the number of elements and things like that, but I am always getting `EXC_BAD_ACCESS`.

How do I use `NSJSONSerialization` to parse the JSON above, and turn it into the data structure I mentioned?


How to use NSJSONSerialization

In my iOS 5 app, I have an `NSString` that contains a JSON string. I would like to deserialize that JSON string representation into a native `NSDictionary` object.

     &quot;{\&quot;password\&quot; : \&quot;1234\&quot;,  \&quot;user\&quot; : \&quot;andreas\&quot;}&quot;
 
### I tried the following approach:

    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:@&quot;{\&quot;2\&quot;:\&quot;3\&quot;}&quot;
                                    options:NSJSONReadingMutableContainers
                                      error:&amp;e];  

### But it throws the a runtime error. What am I doing wrong?

    -[__NSCFConstantString bytes]: unrecognized selector sent to instance 0x1372c 
    *** Terminating app due to uncaught exception &#39;NSInvalidArgumentException&#39;,
    reason: &#39;-[__NSCFConstantString bytes]: unrecognized selector sent to instance 0x1372c&#39;

How do I deserialize a JSON string into an NSDictionary? (For iOS 5+)

I just need to ask something as follow.
Suppose I am having a dictionary.

	NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init];
	[xyz setValue:@&quot;sagar&quot; forKey:@&quot;s&quot;];
	[xyz setValue:@&quot;amit&quot; forKey:@&quot;a&quot;];
	[xyz setValue:@&quot;nirav&quot; forKey:@&quot;n&quot;];
	[xyz setValue:@&quot;abhishek&quot; forKey:@&quot;a&quot;];
	[xyz setValue:@&quot;xrox&quot; forKey:@&quot;x&quot;];


Now, I need to check as follows

[xyz does contains key &quot;b&quot; value ?? pair or not?

Question is How? 

The other question is How to just count total key-value pair?

Say for example `NSInteger mCount=[xyz keyCounts];`


NSDictionary - Need to check whether dictionary contains key-value pair or not

I was using a `NSMutableArray` and realized that using a dictionary is a lot simpler for what I am trying to achieve.

I want to save a key as a `NSString` and a value as an `int` in the dictionary. How is this done?  Secondly, what is the difference between mutable and a normal dictionary?

How to add to an NSDictionary


I have an array of dictionaries.

I want to filter the array based on a key.

I tried this:
 

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@&quot;(SPORT ==  %@)&quot;, @&quot;Football&quot;];
    
    NSArray *filteredArray = [data filteredArrayUsingPredicate:predicate];

This doesn&#39;t work, I get no results. I think I&#39;m doing something wrong. I know this is the method if &quot;SPORT&quot; was an ivar. I think it is probably different if it is a key.

I haven&#39;t been able to find an example however.


Thanks


----------

**Update**

I added quotes around the string I am searching for.

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@&quot;(SPORT ==  &#39;%@&#39;)&quot;, @&quot;Football&quot;];

It still does not work.


----------

**Update 2**

Solved it. I actually had to remove the single quotes, which seems to go against what the guide says.

My real problem is I had a nested array and I wasn&#39;t actually evaluating the dictionaries. Bone head move.



Using NSPredicate to filter an NSArray based on NSDictionary keys

I have one `NSDictionary` and it loads up `UITableView`. If a user scrolls more and more, I call API and pull new data. This data is again in the form of an `NSDictionary`. Is it possible to add the new `NSDictionary` to the existing one?

Appending NSDictionary to other NSDictionary

Is it possible to get all the keys from a specific `NSDictionary` as a seperate `NSArray`?

Get all keys of an NSDictionary as an NSArray

I have the following data saved as an `NSString` : 

     {
        Key = ID;
        Value =         {
            Content = 268;
            Type = Text;
        };
    },
        {
        Key = ContractTemplateId;
        Value =         {
            Content = 65;
            Type = Text;
        };
    },

I want to convert this data to an `NSDictionary` containing the key value pairs.

I am trying first to convert the `NSString` to a **JSON** objects as follows :

     NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    id json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

However when I try :

    NSString * test = [json objectForKey:@&quot;ID&quot;];
    NSLog(@&quot;TEST IS %@&quot;, test);

I receive the value as `NULL`. 

Can anyone suggest what is the problem ?


Converting NSString to NSDictionary / JSON

I have an NSDictionary (stored in a plist) that I&#39;m basically using as an associative array (strings as keys and values).  I want to use the array of keys as part of my application, but I&#39;d like them to be in a specific order (not really an order that I can write an algorithm to sort them into).  I could always store a separate array of the keys, but that seems kind of kludgey because I&#39;d always have to update the keys of the dictionary as well as the values of the array, and make sure they always correspond.  Currently I just use [myDictionary allKeys], but obviously this returns them in an arbitrary, non-guaranteed order.  Is there a data structure in Objective-C that I&#39;m missing?  Does anyone have any suggestions on how to more elegantly do this?


NSDictionary with ordered keys

Can we get the key for an object in an `NSDictionary` by passing a particular value or object?

NSDictionary Key For Value/Object?

how can I check if this exists?:

    [[dataArray objectAtIndex:indexPathSet.row] valueForKey:@&quot;SetEntries&quot;]

I want to know whether this key exists or not. How can I do that?

Thank you very much :)

**EDIT:
dataArray has Objects in it. And these objects are NSDictionaries.**

Check key exists in NSDictionary

I&#39;m struggling with trying to sort an array of dictionaries.

My dictionaries have a couple of values of interest, price, popularity etc.

Any suggestions?

Best way to sort an NSArray of NSDictionary objects?

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?

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

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 = &quot;Ryul INJ&quot;;
        type = Product;
    },
        {
        brand = Trol;
        productTitle = Different;
        quantity = 2;
        subBrand = &quot;&quot;;
        type = Brand;
    },
        {
        brand = Dtor;
        productTitle = Any;
        quantity = 1;
        subBrand = &quot;&quot;;
        type = Product;
    },
        {
        brand = Ryul;
        productTitle = Different;
        quantity = 2;
        subBrand = &quot;Ryul CHES&quot;;
        type = SubBrand;
    },
        {
        brand = Anan;
        productTitle = Any;
        quantity = 1;
        subBrand = &quot;&quot;;
        type = Product;
    }
    )


Normally for sorting an array I will use 

    myArray = [uniqueProdsArray sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

But how do sort using the `brand` key of the dictionary?

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

I am trying to put the content of an NSDictionary into an NSString for testing, But have no idea how to achieve this. Is it possible? if so how would one do such a thing?

The reason I am doing this, Is I need to check the content of a NSDicitonary without the debugger running on my device. as I have to delete the running app from multitasking bar of the ios so I can see if the values I am saving into the dictionary are still available afterwards.

convert NSDictionary to NSString

I am not sure if I am using the dictionary or the data object or both incorrectly. I m trying to get used to the switch to swift but I&#39;m having a little trouble.

    var dictionaryExample : [String:AnyObject] =
        [&quot;user&quot;:&quot;UserName&quot;,
         &quot;pass&quot;:&quot;password&quot;,
        &quot;token&quot;:&quot;0123456789&quot;,
        &quot;image&quot;:0] // image should be either NSData or empty
    
    let dataExample : NSData = dictionaryExample as NSData

I need the `NSDictionary` to encode to an `NSData` object as well as taking that `NSData` object and decode it into a `NSDictionary`.

Any help is greatly appreciated, thanks.

All Nsdictionary Solutions on Gang of Coders

Total of 24 Nsdictionary Solutions