Lookup value associated with key and return the address to it. If the key has not been added, it adds it and returns the address to the new value.
key to lookup the value for
the address to the value associated with key. If key does not exist, it is added and the address to the new value is returned.
See Implementation
Lookup value associated with key and return the address to it. If the key has not been added, it adds it and returns the address to the new value.