Question

hi i have this string { “data”: [ { “name”: “Lorena Trujillo”, “id”: “500144123” }, { “name”: “George Arcila”, “id”: “520311359” }, { “name”: “Laura Victoria Mu\u00f1oz Rincon”, “id”: “528543677” }, { “name”: “Camilo Andres Santacoloma Mejia”, “id”: “529547832” }],”paging”: { “next”: “https://graph.facebook.com/537223119/friends?access_token=AAAAAAITEghMBAI7cZBdbAHt3ZC24esi4ZA6O6kFdwU1H0ekDmGQGRZCUZAVW3T6W6fzg50jHsdfsdfsfdsfdsfzdixf1RrTFLzV96ZBWXAZDZD&limit=5000&offset=5000&__after_id=1000456456455” }

}

and y need extract the substring between [ and ] i use the next code

NSRange startRange = [strFriends rangeOfString:@"["];
NSRange endRange = [strFriends rangeOfString:@"]"];
NSString *formData = [strFriends  substringWithRange:NSMakeRange(startRange.location,endRange.location)];
NSLog(@"this is the data %@",formData); 

and the result is

[ { “name”: “Lorena Trujillo”, “id”: “500144123” }, { “name”: “George Arcila”, “id”: “520311359” }, { “name”: “Laura Victoria Mu\u00f1oz Rincon”, “id”: “528543677” }, { “name”: “Camilo Andres Santacoloma Mejia”, “id”: “529547832” }],”pagin

any idea why these last characters appear ,”pagin thank you very much

Answer 1

This is because startRange location and endRange location both point to the location within the string – but subStringWithRange takes a location and a length – so you need to calculate the length of the string you want to extract. Like this:

NSUInteger dataLength = endrange.location - startRange.location;
NSString *formData = [strFriends  substringWithRange:NSMakeRange(startRange.location,dataLength)];

Besides that, you really need a JSON parser for parsing JSON. Picking out small substrings like this is going to be a lot of work and brittle.