Search results
Results From The WOW.Com Content Network
An invocation of gethash actually returns two values: the value or substitute value for the key and a boolean indicator, returning T if the hash table contains the key and NIL to signal its absence. ( multiple-value-bind ( value contains-key ) ( gethash "Sally Smart" phone-book ) ( if contains-key ( format T "~&The associated value is: ~s ...
However, a single patron may be able to check out multiple books. Therefore, the information about which books are checked out to which patrons may be represented by an associative array, in which the books are the keys and the patrons are the values. Using notation from Python or JSON, the data structure would be:
Trie-Find(x, key) for 0 ≤ i < key.length do if x.Children[key[i]] = nil then return false end if x := x.Children[key[i]] repeat return x.Value In the above pseudocode, x and key correspond to the pointer of trie's root node and the string key respectively.
A complex-valued data record must be stored using the "annotated array format". This is achieved via the presence of _ArrayIsComplex_ keyword and the serialization of the complex values in the _ArrayData_ constructs in the order of [[serialized real-part values], [serialized imag-part values]]
The simplest kind of query is to locate a record that has a specific field (the key) equal to a specified value v. Other common kinds of query are "find the item with smallest (or largest) key value", "find the item with largest key value not exceeding v ", "find all items with key values between specified bounds v min and v max ".
For that reason, the elements of an array data structure are required to have the same size and should use the same data representation. The set of valid index tuples and the addresses of the elements (and hence the element addressing formula) are usually, [3] [5] but not always, [2] fixed while the array is in use.
A tabular data card proposed for Babbage's Analytical Engine showing a key–value pair, in this instance a number and its base-ten logarithm. A key–value database, or key–value store, is a data storage paradigm designed for storing, retrieving, and managing associative arrays, and a data structure more commonly known today as a dictionary or hash table.
A related notion is that of a compressed data structure, insofar as the size of the stored or encoded data similarly depends upon the specific content of the data itself. Suppose that is the information-theoretical optimal number of bits needed to store some data. A representation of this data is called: