3.5 The dictionary type

delete($$s$)$
The delete($$s$) method deletes any element with string key $s$ from the dictionary. $

hasKey($$x$)$
The hasKey($$x$) method returns a boolean indicating whether the key $x$ exists in the dictionary. $

items()
The items() method returns a list of the [key,value] pairs in a dictionary.

keys()
The keys() method returns a list of the keys defined in a dictionary.

len()
The len() method returns the number of entries in a dictionary.

values()
The values() method returns a list of the values in a dictionary.