Dictionary

Dictionaries are collection objects that associate a unique key with a particular value. Keys can be any kind of morpho value, including numbers, strings and objects.

An example dictionary mapping states to capitals:

var dict = { "Massachusetts" : "Boston",
             "New York" : "Albany",
             "Vermont" : "Montpelier" }

Look up values by a given key with index notation:

print dict["Vermont"]

You can change the value associated with a key, or add new elements to the dictionary like this:

dict["Maine"]="Augusta"

Create an empty dictionary using the Dictionary constructor function:

var d = Dictionary()

Loop over keys in a dictionary:

for (k in dict) print k

The keys method returns a Morpho List of the keys.

var keys = dict.keys() // will return ["Massachusetts", "New York", "Vermont"]

The contains method returns a Bool value for whether the Dictionary contains a given key.

print dict.contains("Vermont") // true
print dict.contains("New Hampshire") // false

The remove method removes a given key from the Dictionary.

dict.remove("Vermont")
print dict // { New York : Albany, Massachusetts : Boston }

The clear method removes all the (key, value) pairs fromt the dictionary, resulting in an empty dictionary.

dict.clear()

print dict // {  }