I have an NSDictionary that I fill with JSON. It all looks great, and it is partially working for me. I am setting a property of my class that is of type NSString equal to a value for a certain key, which oddly enough sets my property equal to an object with the object being the string value I need.
The dictionary (printed description):
miscInfo:
<__NSArrayI 0x7494ab0>(
{
Abbreviation = DR;
DateInactive = "";
Description = Drowsiness;
ForQueue = 2430;
IsAdditive = 0;
IsReserved = 1;
MiscCodeTypeStr = AVR;
PluralDescription = "";
ReservedDescription = Drowsiness;
}
I am setting it on my property like so:
self.ReactionName = [miscInfo valueForKeyPath:#"Description"];
Which produces:
I've tried casting it as NSString such as:
self.ReactionName = (NSString*)[allergenAdverseReaction valueForKeyPath:#"Description"];
but nothing gives. What am I doing wrong?
miscInfo is an array containing a dictionary, so
self.ReactionName = [[miscInfo objectAtIndex:0] objectForKey:#"Description"];
would give the result that you expect. Or, using the modern array and dictionary
subscripting syntax:
self.ReactionName = miscInfo[0][#"Description"];
Remark: In your code
self.ReactionName = [miscInfo valueForKeyPath:#"Description"];
valueForKeyPath is applied to each element of the array, and an array with all
the values is returned. That is what you see in the Xcode debugger window.
This "feature" can be very useful, but in general (as Hot Licks commented above)
objectForKey is the right method to get a value from a dictionary. And
self.ReactionName = [miscInfo objectForKey:#"Description"];
throws a descriptive runtime exception if miscInfo is not a dictionary as expected.
It looks to me like miscInfo is an array of dictionaries. In that case valueForKey will return an array. See if the code below works. If it does, then it is an array of dictionaries.
self.ReactionName = [[allergenAdverseReaction valueForKeyPath:#"Description"]lastObject];
Related
This is part of an incoming array:
variantArray: (
(
{
CardinalDirection = "North-West";
DirectionVariantId = "DcCi_1445_171_0_0";
Distance = "2.516606318971459";
RouteName = "Woodsy";
Shape = {
Points = (
{
I want to get the value of DirectionVariantId
I would normally loop and use
NSMutableArray *myString = [variantArray[i] valueForKey:#"DirectionVariantId"];
This isn't working and results in an exception when I try to examine the last character in the string:
NSString *lastChar = [myString substringFromIndex:[myString length] - 1];
This is a new data set for me and I'm missing something..
Thanks for any tips.
Json contain two curly bracket means nested array.
Try:
NSString *myString=[[[variantArray objectAtIndex:0] objectAtIndex:0] objectForKey:#"DirectionVariantId"];
I think you're looking for [variantArray[i] objectForKey:#"DirectionVariantId"];
You'd need to convert the object within your incoming array (variantArray[i]) to a NSDictionary but it might already be judging by your original output.
When I do an operation like this:
self.slider.value = randomArray[0][0];
I would like to be able to do this:
self.slider.value = randomArray[randomVariable][0];
Basically, how do you put that "randomVariable" in the brackets? When I try to do this on Xcode, I get:
Code: self.detail1.text = detailsForNotesUse[x][0];
Error:Expected Method to read dictionary element not found in object
of type 'NSArray *'
The variable I put in the brackets is NSString, the array is NSArray, and detail1 is a text field.
Declarations:
NSString *x = 0;
NSArray *detailsForNotesUse;
You've defined x as an NSString. You should define your index variable like this:
NSUInteger x = 0;
I'm just reposting the answer I gave in my comment below the question:
x needs to be an int if you're using it as an index. ex. int x = 0;
But I'm also writing to note that many of the answers are misleading. You can in fact access a nested array in this way, i.e. randomArray[x][y];, because if randomArray[x] returns an array (as is syntactically valid in obj-c), the items of that array can then be similarly accessed by appending [y] (though you may have to cast randomArray[x] to an NSArray to prevent a warning).
for (NSDictionary *fbDictionary in self.latestReactionsArray) {
LatestReaction *latestReaction = [[LatestReaction alloc]init];
NSDictionary *subFBDictionary = [fbDictionary objectForKey:#"participant"];
NSString *facebookUserID = [subFBDictionary valueForKey:#"facebook_id"];
NSNumber* reactionIDNum = [fbDictionary valueForKey:#"reaction_id"];
int reactionID = [reactionIDNum intValue];
NSLog(#"what is name%# and %# and %d",facebookUserID, self.latestReactionsArray,reactionID);
}
I want to save all [fbDictionary valueForKey:#"reaction_id"] in an array or dictionary. How do I do this? Thanks.
Try this:
NSArray *reactionIDs = [self.latestReactionsArray valueForKey:#"reaction_id"];
That will give you an array of reaction IDs.
The reflection in Objective C is not powerful enough to get a usable list of properties that you want to map. Instead, you should implement a class method that returns a list of properties you want to map to JSON and use that.
Lastly, a common "Gotcha" is trying to add nil to a dictionary. You'll need to do a conversion from nil to [NSNull null] and back for the conversion to work properly.
So I have a basic array:
NSMutableArray *answerButtonsArrayWithURL = [NSMutableArray arrayWithObjects:self.playView.coverURL1, self.playView.coverURL2, self.playView.coverURL3, self.playView.coverURL4, nil];
The objects inside are strings. I want to access a random object from that array
int rndValueForURLS = arc4random() % 3;
and assigning it a value. I've tried manny different approaches but my recent one is
[[answerButtonsArrayWithURL objectAtIndex:rndValueForURLS] stringByAppendingString:[self.coverFromRightAnswer objectAtIndex:self.rndValueForQuestions]];
Any help will be much appreciated. Thanks
You need to assign it. You're already building the new value like that:
NSString *oldValue = answerButtonsArrayWithURL[rndValueForURLS];
NSString *newValue = [oldValue stringByAppendingString:[self.coverFromRightAnswer objectAtIndex:self.rndValueForQuestions]];
The part you're missing :
answerButtonsArrayWithURL[rndValueForURLS] = newValue;
Above would be the way to replace the immutable string with another. If the strings are mutable, that is, they were created as NSMutableString, you could do:
NSMutableString *value = answerButtonsArrayWithURL[rndValueForURLS];
[value appendString:[self.coverFromRightAnswer objectAtIndex:self.rndValueForQuestions]];
Note:
Everywhere I replace the notation :
[answerButtonsArrayWithURL objectAtIndex:rndValueForURLS];
with the new equivalent and IMO more readable:
answerButtonsArrayWithURL[rndValueForURLS];
I have a webservice that returns data to my client application in JSON. I am using TouchJson to then deserialize this data into a NSDictionary. Great. The dictionary contains a key, "results" and results contains an NSArray of objects.
These objects look like this when printed to log i.e
NSLog(#"Results Contents: %#",[resultsArray objectAtIndex:0 ]);
Outputs:
Results Contents: {
creationdate = "2011-06-29 22:03:24";
id = 1;
notes = "This is a test item";
title = "Test Item";
"users_id" = 1;
}
I can't determine what type this object is. How do I get the properties and values from this object?
Thanks!
To get the content of a NSDictionary you have to supply the key for the value that you want to retrieve. I.e:
NSString *notes = [[resultsArray objectAtIndex:0] valueForKey:#"notes"];
To test if object is an instance of class a, use one of these:
[yourObject isKindOfClass:[a class]]
[yourObject isMemberOfClass:[a class]]
To get object's class name you can use one of these:
const char* className = class_getName([yourObject class]);
NSString *className = NSStringFromClass([yourObject class]);
For an NSDictionary, you can use -allKeys to return an NSArray of dictionary keys. This will also let you know how many there are (by taking the count of the array). Once you know the type, you can call
[[resultsArray objectAtIndex:0] objectForKey:keyString];
where keyString is one of #"creationdate", #"notes", etc. However, if the class is not a subclass of NSObject, then instead use:
[[resultsArray objectAtIndex:0] valueForKey:keyString];
for example, you probably need to do this for keystring equal to #"id".