creating JSON format in Objective C - iphone

Question

For an application i want to create a JSON in format as mentioned below,
"Students" : {
"results": {
"Grade1": {
"studentresult": "pass",
"marksheet": "provided"
},
"ID": 01,
"Name": "Student1",
}
}
I am using the following code to create the same,
NSMutableDictionary *gradedetails = [[NSMutableDictionary alloc] init];
[gradedetails setObject:#"pass" forKey:#"studentresult"];
[gradedetails setObject:#"provided" forKey:#"marksheet"];
NSMutableDictionary *sdetails = [[NSMutableDictionary alloc] init];
[sdetails setObject:#"01" forKey:#"ID"];
[sdetails setObject:#"Name" forKey:#"Student1"];
NSMutableDictionary *grade = [[NSMutableDictionary alloc] init];
[grade setObject:gradedetails forKey:#"Grade1"];
NSMutableArray *rarray = [[NSMutableArray alloc] init];
[rarray addObject:grade];
[rarray addObject:sdetails];
NSMutableDictionary *results = [[NSMutableDictionary alloc] init];
[results setObject:rarray forKey:#"results"];
NSMutableDictionary *stud = [[NSMutableDictionary alloc] init];
[stud setObject:rdic forKey:#"Students"];
NSData *jsondata = [NSJSONSerialization dataWithJSONObject:stud options:NSJSONWritingPrettyPrinted error:&error];
I am getting in the following format,
"Students" : {
"results" : [
{
"Grade1" : {
"studentresult" : "pass",
"marksheet" : "provided"
}
},
{
"ID" : "01",
"Name" : "Student1"
}
]
}
}
could someone please help me in creating the format.
Thanks.

Answer 1

Required Data , You can get this way . Just convert that stud dict in JSon or any other format you want. Remove that array , You don't need it , As you mentioned it in the required format.
NSMutableDictionary *gradedetails = [[NSMutableDictionary alloc] init];
[gradedetails setObject:#"pass" forKey:#"studentresult"];
[gradedetails setObject:#"provided" forKey:#"marksheet"];
NSMutableDictionary *sdetails = [[NSMutableDictionary alloc] init];
[sdetails setObject:#"01" forKey:#"ID"];
[sdetails setObject:#"Name" forKey:#"Student1"];
[sdetails setObject:gradedetails forKey:#"Grade1"];
NSMutableDictionary *results = [[NSMutableDictionary alloc] init];
[results setObject:sdetails forKey:#"results"];
NSMutableDictionary *stud = [[NSMutableDictionary alloc] init];
[stud setObject:results forKey:#"Students"];
NSLog(#"Required Format Data is %#",stud);

Answer 2

Depends on your code:
NSMutableDictionary *gradedetails = [[NSMutableDictionary alloc] init];
[gradedetails setObject:#"pass" forKey:#"studentresult"];
[gradedetails setObject:#"provided" forKey:#"marksheet"];
NSMutableDictionary *results = [[NSMutableDictionary alloc] init];
[results setObject:gradedetails forKey:#"Grade1"];
[results setObject:#"01" forKey:#"ID"];
[results setObject:#"Name" forKey:#"Student1"];
NSMutableDictionary *stud = [[NSMutableDictionary alloc] init];
[stud setObject:results forKey:#"Students"];

Answer 3

NSDictionary *gradedetails = #{#"studentresult" : #"pass", #"marksheet" : #"provided"};
NSDictionary *grade = #{ #"Grade1" : gradedetails}
NSDictionary *sdetails = #{#"ID" : #"01", #"Student1" : #"Name"};
NSArray *resultsArray = #[grade, sdetails];
NSDictionary *results= #{#"results" : resultsArray};
NSDictionary *stud = #{#"Students" : results};
NSData *jsondata = [NSJSONSerialization dataWithJSONObject:stud options:NSJSONWritingPrettyPrinted error:&error];
I wonder why few developper use this notation

Answer 4

check this code-
NSMutableDictionary *students=[NSJSONSerialization JSONObjectWithData:webData options:0 error:nil];
for (NSDictionary *dictionofstudents in students)
{
NSMutableDictionary *results=[dictionofstudents objectForKey:#"results"];
for (NSDictionary *dictionofresults in results)
{
NSMutableDictionary *grade1=[dictionofresults objectForKey:#"Grade1"];
for (NSDictionary *dictionofgrade1 in grade1)
{
NSString *studentresult=[dictionofgrade1 objectForKey:#"studentresult"];
NSString *marksheet=[dictionofgrade1 objectForKey:#"marksheet"];
[arrayofstudentresult addObject:studentresult];
[arrayofmarksheet addObject:marksheet];
}
NSString *ID=[dictionofresults objectForKey:#"ID"];
NSString *name=[dictionofresults objectForKey:#"Name"];
[arrayofID addObject:ID];
[arrayofname addObject:name];
}
}

Answer 5

In order to get the format you want out of it, you have to pack information in that particular format.
Your problem is right about here:
NSMutableArray *rarray = [[NSMutableArray alloc] init];
[rarray addObject:grade];
[rarray addObject:sdetails];
The desired format has no arrays, so why are you creating an array?
A hint for you:
You should be creating exactly 4 dictionaries, and no arrays.

Answer 6

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
NSMutableDictionary *result = [[NSMutableDictionary alloc] init];
NSMutableDictionary *grade = [[NSMutableDictionary alloc] init];
[grade setValue:#"pass" forKey:#"studentresult"];
[grade setValue:#"provided" forKey:#"marksheet"];
[result setValue:grade forKey:#"Grade1"];
[result setValue:#"01" forKey:#"ID"];
[result setValue:#"Student1" forKey:#"Name"];
[dict setValue:result forKey:#"results"];
NSMutableDictionary *stdnt = [[NSMutableDictionary alloc] init];
[stdnt setValue:dict forKey:#"Students"];
NSError *error = nil;
NSData *jsondata = [NSJSONSerialization dataWithJSONObject:stdnt options:NSJSONWritingPrettyPrinted error:&error];
NSString *s = [[NSString alloc] initWithData:jsondata encoding:NSUTF8StringEncoding];
NSLog(#"%#",s);
It may helps you.