'+[NSDictionary dictionaryWithObjectsAndKeys:]: second object of each pair must be non-nil. Or, did you forget to nil-terminate your parameter list?'
<p>am post mycode to json but my app error   </p>

<blockquote>
  <p>" Terminating app due to uncaught exception
  'NSInvalidArgumentException', reason: '+[NSDictionary
  dictionaryWithObjectsAndKeys:]: second object of each pair must be
  non-nil.  Or, did you forget to nil-terminate your parameter list?'"</p>
</blockquote>

<pre><code>-(void)requesdatesendorder:(NSArray *)foodid{
NSString *FoodId ;

for (int i =0; i &lt; foodid.count; i++) {
    NSString *idfood = [foodid objectAtIndex:i];
    if (FoodId.length == 0) {
        FoodId = [NSString stringWithFormat:@"%@,food_id[%d]",idfood,i];
    }
    else{
        FoodId = [NSString stringWithFormat:@"%@,%@,food_id[%d]",FoodId,idfood,i];
    }
}

NSLog(@"%@",FoodId);

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                        @"date_send_order",@"params",
                        FoodId
                        ,nil];
[self requestWithMethod:@"POST"
              urlString:kFeedBeeservice
             parameters:params
                   mode:Beeservicedatesendorder];
}
</code></pre>

<p>but i want send json format
<a href="http://i.stack.imgur.com/tkfqv.png" rel="nofollow">http://i.stack.imgur.com/tkfqv.png</a></p>