JSON Parsing of ios - ios

Question

I am trying to parse the below JSON but am not getting the data from this JSON.
In the below JSON I am trying to fetch choices but its not getting with my below code
NSString *filePathChoices = [[NSBundle mainBundle] pathForResource:#"questions" ofType:#"json"];
NSData *JSONDataChoices = [NSData dataWithContentsOfFile:filePathChoices options:NSDataReadingMappedIfSafe error:nil];
NSMutableDictionary *jsonObjectChoices = [NSJSONSerialization JSONObjectWithData:JSONDataChoices options:NSJSONReadingMutableContainers error:nil];
NSArray *arrayChoices = [jsonObjectChoices objectForKey:#"choices"];
//NSDictionary *jsonDict = [arrayChoices objectAtIndex:indexPath.row];
cell.textLabel.text = [arrayChoices objectAtIndex:indexPath.row];
From this below JSON i am fetching the choices into tableview
{
"questions": [
{
"question": "1. An ITM option has is priced at $3.00. The strike is at $20 and the underlying is trading at $19. What is the extrinsic value of the option?",
"choices": ["Ontario","New Brunswick","Manitoba","Quebec"],
"correctAnswer": 0
},
{
"question": "2. True or False. If a trader is long some calls and long some puts, he is likely to be?",
"choices": ["Ontario", "New Brunswick", "Nova Scotia", "Quebec"],
"correctAnswer": 3
},
{
"question": "3. Which of these provinces start with 'New'?",
"choices": ["Ontario", "New Brunswick", "Quebec", "Manitoba"],
"correctAnswer": 1
},
{
"question": "4. Which of these begin with the word 'Man'?",
"choices": ["Ontario", "New Brunswick", "Quebec", "Manitoba"],
"correctAnswer": 3
},
{
"question": "5. Which of these begin with the word 'Nova'?",
"choices": ["Ontario", "Nova Scotia", "British Columbia", "New Brunswick"],
"correctAnswer": 1
},
]
}

Answer 1

Choice is not on the top level.
So if you data structure is exactly as you've described it, you first need to get a question, and then get choice on this question.
Example:
NSArray *questions = [jsonObjectChoices objectForKey:#"questions"];
Now, get a question (here we take the first one)
NSDictionnary *question=[questions objectAtIndex:0]
And then, if you want to get the choices for this question
NSArray *choices=[question objectForKey:#"choices"];

Answer 2

you can't directly dispaly the array of values in cell. Replace the code with below code to solve it
NSString *filePathchoice = [[NSBundle mainBundle] pathForResource:#"questions" ofType:#"json"];
NSData *JSONData = [NSData dataWithContentsOfFile:filePathchoice options:NSDataReadingMappedIfSafe error:nil];
NSDictionary *jsonObject = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableContainers error:nil];
NSArray *array = [jsonObject objectForKey:#"questions"];
questions = [[NSMutableArray alloc] initWithCapacity:[array count]];
for (NSDictionary *dict in array) {
question = [[Question alloc] initWithObject:dict];
[questions addObject:question];
}
cell.textLabel.text = [choices objectAtIndex:indexPath.row];
cell.textLabel.font=[UIFont fontWithName:#"Bold" size:12];

Answer 3

Your json is not vaild modify your json file as below and try
{
"questions": [
{
"question": "1. An ITM option has is priced at $3.00. The strike is at $20 and the underlying is trading at $19. What is the extrinsic value of the option?",
"choices": [
"Ontario",
"New Brunswick",
"Manitoba",
"Quebec"
],
"correctAnswer": 0
},
{
"question": "2. True or False. If a trader is long some calls and long some puts, he is likely to be?",
"choices": [
"Ontario",
"New Brunswick",
"Nova Scotia",
"Quebec"
],
"correctAnswer": 3
},
{
"question": "3. Which of these provinces start with 'New'?",
"choices": [
"Ontario",
"New Brunswick",
"Quebec",
"Manitoba"
],
"correctAnswer": 1
},
{
"question": "4. Which of these begin with the word 'Man'?",
"choices": [
"Ontario",
"New Brunswick",
"Quebec",
"Manitoba"
],
"correctAnswer": 3
},
{
"question": "5. Which of these begin with the word 'Nova'?",
"choices": [
"Ontario",
"Nova Scotia",
"British Columbia",
"New Brunswick"
],
"correctAnswer": 1
}
] }

Answer 4

The go to library I use in my projects is JsonModel.
Example one line request to get the json.
[JSONHTTPClient postJSONFromURLWithString:#"http://example.com/api"
params:#{#"postParam1":#"value1"}
completion:^(id json, JSONModelError *err) {
//check err, process json ...
}];
For this json :
{
"order_id": 104,
"total_price": 103.45,
"products" : [
{
"id": "123",
"name": "Product #1",
"price": 12.95
},
{
"id": "137",
"name": "Product #2",
"price": 82.95
}
]
}
You only need to subclass JSONModel and add this to your .h file :
#protocol ProductModel
#end
#interface ProductModel : JSONModel
#property (assign, nonatomic) int id;
#property (strong, nonatomic) NSString* name;
#property (assign, nonatomic) float price;
#end
#implementation ProductModel
#end
#interface OrderModel : JSONModel
#property (assign, nonatomic) int order_id;
#property (assign, nonatomic) float total_price;
#property (strong, nonatomic) NSArray<ProductModel, ConvertOnDemand>* products;
#end
#implementation OrderModel
#end
Advantages JSONModel :
One line fetches for json / or you can choose another fetch method.
Easily convert JSONModel objects to / from NSDictionary, text.
Optional parameters, direct conversion to the data types you specify
and custom error handling and many more.
Installation :
Clone source, copy paste the JSONModel folder into your project.
Subclass JSONModel, add the matching properties from json to your
header file (be careful, if your json is potentially malformatted,
you should use the parameter that instructs the framework
that in your json, these could be null or missing).
Fetch and parse your json like in your above example, and then test
all of the properties for inconsistencies.
In your example, you have a "," in plus, just before "]"
The corrected code :
{
"questions": [
{
"question": "1. An ITM option has is priced at $3.00. The strike is at $20 and the underlying is trading at $19. What is the extrinsic value of the option?",
"choices": [
"Ontario",
"New Brunswick",
"Manitoba",
"Quebec"
],
"correctAnswer": 0
},
{
"question": "2. True or False. If a trader is long some calls and long some puts, he is likely to be?",
"choices": [
"Ontario",
"New Brunswick",
"Nova Scotia",
"Quebec"
],
"correctAnswer": 3
},
{
"question": "3. Which of these provinces start with 'New'?",
"choices": [
"Ontario",
"New Brunswick",
"Quebec",
"Manitoba"
],
"correctAnswer": 1
},
{
"question": "4. Which of these begin with the word 'Man'?",
"choices": [
"Ontario",
"New Brunswick",
"Quebec",
"Manitoba"
],
"correctAnswer": 3
},
{
"question": "5. Which of these begin with the word 'Nova'?",
"choices": [
"Ontario",
"Nova Scotia",
"British Columbia",
"New Brunswick"
],
"correctAnswer": 1
}
]
}
The model that you can use to parse this :
#interface QuestionsFetch : JSONModel
#property (strong, nonatomic) NSArray<QuestionModel>* questions;
#protocol QuestionModel #end
#interface QuestionModel : JSONModel
#property (strong, nonatomic) NSString* question;
#property (strong, nonatomic) NSArray<ChoicesModel>* choices;
#protocol ChoicesModel #end
#interface ChoicesModel : JSONModel
#property (strong, nonatomic) NSArray* choice;
If you have any problems with importing / parsing, leave a comment.