How to insert a new key with value in dictionary

Question

I want to insert a key with a corresponding value in an existing dictionary...

I am able to set values for existing keys in the dictionary, but I am not able to add

Answer 1

NSMutableDictionary *dict = [[NSMutableDictionary alloc]init];

By using this method we can add the new value to NSMutableDictionary

[dict setObject:@"Value" forKey:@"Key"];

To know wheather the key exist in dictionary

[[dict allKeys] containsObject:@"key"];