NSDictionary *aDictionary = [[NSDictionary alloc]initWithObjectsAndKeys:@"tom",@"",@"alex",@"",@"josen",@"", nil];
[aDictionary enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL *stop) {
NSLog(@"value for key %@ is %@", key, value);
if ([@"" isEqualToString:key]) {
*stop = YES; }
}]; NSArray *aArray = [[NSArray alloc]initWithObjects:@"",@"",@"",@"",@"", nil];
[aArray enumerateObjectsUsingBlock:^(id obj, NSUInteger index, BOOL *stop){
NSLog(@"----%@ ---%ld",[aArray objectAtIndex:index],index);
if (index == ) {
*stop = YES; }
}];