ABSTRACT
The abstract data structure Dictionary is defined as a collection of key-value pairs, supporting the operations of inserting, deleting, and searching a value by its associated key. Although not clearly stated in the definition, an assumption is adopted that an order is imposed on the keys. Implementations of the Dictionary data structure pursue high efficiencies on the operations of inserting, deleting, and searching. For example, these operations can be performed effectively on a hash table or a binary search tree. The order of the keys is a potential resource to provide some conveniences to access the values. However, a dictionary is not required to provide operations manipulating the values through the order of their keys.
