Objective C: Serialize to JSON

gistfile1.txt

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{

    @autoreleasepool {

        NSDictionary *attributes = @{ @"first": @"first value",
                                      @"second" : @3.14,
                                      @"third" : @[ @"one", @"two", @4, @5, @YES, @NO] };
        
        if ( [NSJSONSerialization isValidJSONObject:attributes] ) {
            NSError *error = nil;
            NSData *json = [NSJSONSerialization dataWithJSONObject:attributes options:NSJSONWritingPrettyPrinted error:&error];
            if ( json && !error ) {
                NSString *jsonString = [[NSString alloc] initWithData:json encoding:NSUTF8StringEncoding];
                NSLog(@"json: %@", jsonString);
                // Same written to a file
                [jsonString writeToFile:@"json_file.json" atomically:YES encoding:NSUTF8StringEncoding error:&error];
            }
        }
    }
    return 0;
}