iOS: write data to json file programatically - objective-c

Question

My json file look like this:
{
"images": [
"straight up kick.png",
"women kick.png",
"Taekwondo Kanji vertical.png",
"face kick3.png",
"flexibility.png",
"Punch.png",
"hook kick.png",
"front kick 2.png"
]
}
i am reading above json programmatically like below:
NSString *path = [[NSBundle mainBundle] pathForResource:#"generated" ofType:#"json"];
NSData *data = [NSData dataWithContentsOfFile:path];
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
NSMutableArray * jsonimages = [dict objectForKey:#"images"];
NSLog(#"images %#", jsonimages);
i want to add more items to array named as jsonimages by writing to json file programmatically.
Json file name is generated.json.
Any help would be appreciated.

Answer 1

- (void)writeStringToFile:(NSString*)aString {
// Build the path, and create if needed.
NSString* filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* fileName = #"generated.json";
NSString* fileAtPath = [filePath stringByAppendingPathComponent:fileName];
if (![[NSFileManager defaultManager] fileExistsAtPath:fileAtPath]) {
[[NSFileManager defaultManager] createFileAtPath:fileAtPath contents:nil attributes:nil];
}
// The main act...
[[aString dataUsingEncoding:NSUTF8StringEncoding] writeToFile:fileAtPath atomically:NO];
}
- (NSString*)readStringFromFile {
// Build the path...
NSString* filePath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString* fileName = #"generated.json";
NSString* fileAtPath = [filePath stringByAppendingPathComponent:fileName];
// The main act...
return [[NSString alloc] initWithData:[NSData dataWithContentsOfFile:fileAtPath] encoding:NSUTF8StringEncoding];
}