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POJSON parser returns Null
 

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  1. POJSON parser returns Null
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    <p>I am trying to learn how to parse JSON data so I can handle big databases. I wrote code to login into a website.</p> <p>I have following JSON data from a successful login request:</p> <pre><code>JSON string : correct username and password [{"user_id":"7","first_name":"dada","last_name":"Kara","e_mail":"yaka@gmail","fullname":"Dada Kara","forum_username":"ycan"}] </code></pre> <p>and i use following code to parse but it doesnt parse it</p> <pre><code>-(IBAction)loginButton:(id)sender{ NSString *username = usernameTextfield.text; NSString *password = passwordTextfield.text; NSMutableURLRequest *request =[NSMutableURLRequest requestWithURL:[NSURL URLWithString:kPostUrl]]; [request setHTTPMethod:@"POST"]; NSString *post =[[NSString alloc] initWithFormat:@"e_mail=%@&amp;password=%@", username, password]; [request setHTTPBody:[post dataUsingEncoding:NSASCIIStringEncoding]]; NSURLResponse *response; NSError *err; NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&amp;response error:&amp;err]; //NSString *responseStr = [NSString stringWithUTF8String:[responseData bytes]]; //NSLog(@"Response : %@", responseStr); NSString *json_string = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding]; NSLog(@"JSON string : %@", json_string); SBJsonParser *parser = [[SBJsonParser alloc] init]; NSDictionary *responseObj = [parser objectWithString:json_string error:nil]; NSArray *name = [responseObj objectForKey:@"first_name"]; NSLog(@"Name : %@", name); } </code></pre> <p>The result from my <code>NSLog</code> for name is <code>NULL</code> </p> <p>Where is the problem and how can I parse such a data so when it comes to lots of rows I can save it to the local FMDB database on iphone</p> <p><strong>------------------------------EDIT---------------------------------------------------------------</strong></p> <p>Actual problem was response JSON string from server included echo beginning of the string,json parser only parses between double quotes "", so all i just needed to trim echo from string and parse new string.</p> <p>and bingo!</p> <pre><code>//trim in coming echo NSString *newString1 = [json_string stringByReplacingOccurrencesOfString:@"correct username and password\n" withString:@""]; SBJsonParser *parser = [[SBJsonParser alloc] init]; NSArray *responseObj = [parser objectWithString:newString1 error:nil]; NSDictionary *dataDict = [responseObj objectAtIndex:0]; NSString *userID = [dataDict objectForKey:@"user_id"]; NSLog(@"user_id: %@", userID); </code></pre> <p>output : user_id : 7</p>
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    1. This table or related slice is empty.
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    1. COThe JSON string is an array that contains dictionary, so first extract the dictionary and then parse it.
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    2. COi guess below answer is the one you have mentioned but i still get NULL
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