Tips: How to find if NSDictionary has a key.

if ([[myDiction allKeys] containsObject:@"myKey"])

    NSLog(@"It contains myKey");

Boolean in NSDictionary

You can store a bool value in NSDictionary as following

NSDictionary *aProperties=[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:@"myboolkey"];

 To retrieve a bool value from NSDictionary:

BOOL boolValue;

if([aProperties valueForKey:@"myboolkey"]) 

  boolValue =[[aProperties valueForKey:@"myboolkey"] boolValue];