Q: [__NSCFBoolean rangeOfCharacterFromSet:]: unrecognized selector sent to instance I populated UITableView with JSON data but when I scroll down UITableView it gives upper thread.Please help me to solve this thread.
Thank You 

A: Your JSON data contained a value that you thought was a string but was actually a boolean (true or false). When you parse JSON, you must check every single value that you are processing. You should also read the spec of the JSON that you are processing, but checking is essential because without the checking any hacker can make your app crash at any time. 
It's of course up to you whether you replicate the same ten lines of code for proper checking in a thousand places in your code or whether you write an extension to NSDictionary that does all the checking and catches the problem where it arises instead of crashing your app. 
