Best way get object for key for inner key in NSDictionary?

Question

Maybe this question title is not very clear. I have json as follow:

// {
//    "aps": {
//        "alert": {
//            "title":"nice title",
//            "body":"A nice body. $savings"
//        },
//        "content-available":"1"   //This flag set enables background processing
//    },
//    "blabla":"1",
//    "spend_amount":"$cash",
//    "save_amount":"$savings"
// }

To get info inside title I need to do either:

 NSString * _message = [[[userInfo objectForKey:@"aps"] objectForKey:@"alert"] objectForKey:@"body"];

or define three two variables

id payload = [userInfo objectForKey:@"aps"];
id alert = [payload objectForKey:@"alert"];
NSString * _actionTitle = [alert objectForKey:@"title"];

Is there any nicer way to do this?

yes, using literals: http://stackoverflow.com/questions/9693647/is-there-some-literal-dictionary-or-array-syntax-in-objective-c — luk2302, May 13 '16 at 08:49

Nitin Gohel · Accepted Answer · 2016-05-13T09:03:35.307

3

Try to use following one line of code for getting nested Dictionary keys value:

[userInfo valueForKeyPath:@"aps.alert.title"];

I just Create and example and test code:

    NSMutableDictionary *d =[[NSMutableDictionary alloc]init];
    [d setValue:@"A nice body. $savings" forKey:@"body"];
    [d setValue:@"nice title" forKey:@"title"];


    NSMutableDictionary *b =[[NSMutableDictionary alloc]init];
    [b setValue:d forKey:@"alert"];

    NSMutableDictionary *e =[[NSMutableDictionary alloc]init];

    [e setValue:@"1" forKey:@"content-available"];
    [e setValue:b forKey:@"aps"];

    NSLog(@"Dictioarn = %@",e);
    NSLog(@"Dictioarn = %@",[e valueForKeyPath:@"aps.alert.title"]);

OUTPUT IS:

Dictioarn = nice title

edited May 13 '16 at 09:03

answered May 13 '16 at 08:50

Nitin Gohel

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1

This is the best way. – trojanfoe May 13 '16 at 08:51
`setValue:forKey:` is not cool tho... – trojanfoe May 13 '16 at 09:07
You mean use `setObject:forKey`? – Nitin Gohel May 13 '16 at 09:08
@trojanfoe so what to use instead `setValue:forKey` – Bhavin Bhadani May 13 '16 at 09:09
i got it if we are using mutable object like `NSMutableDictionary` then we have to use `setObject:forKey` and if we are using `NSDictionary` then use `setValue:forKey` – Nitin Gohel May 13 '16 at 09:11

score 0 · Answer 2 · answered May 13 '16 at 08:52

0

Use this code,

change objectForKey instead of valueForKey in body keyword,

NSString * _message = [[[userInfo objectForKey:@"aps"] objectForKey:@"alert"] valueForKey:@"body"];

hope its helpful

answered May 13 '16 at 08:52

Iyyappan Ravi

3,205
2
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This is the worst way. – trojanfoe May 13 '16 at 08:53
I am new in IOS, i used above methods only, Any way thanks for your feedback – Iyyappan Ravi May 13 '16 at 09:08

Best way get object for key for inner key in NSDictionary?

2 Answers2