Search results
Results from the WOW.Com Content Network
Ruby's design forces all instance variables to be private, but also provides a simple way to declare set and get methods. This is in keeping with the idea that in Ruby one never directly accesses the internal members of a class from outside the class; rather, one passes a message to the class and receives a response.
It is primarily associated with PHP, Ruby and Perl programming languages, which use it to declare hashes. Using a fat comma to bind key-value pairs in a hash, instead of using a comma, is considered an example of good idiomatic Perl. [1] In CoffeeScript and TypeScript, the fat comma is used to declare a function that is bound to this. [2] [3]
A hash table uses a hash function to compute an index, also called a hash code, into an array of buckets or slots, from which the desired value can be found. During lookup, the key is hashed and the resulting hash indicates where the corresponding value is stored. A map implemented by a hash table is called a hash map.
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 ...
Ruby 1.9 introduces many significant changes over the 1.8 series. Examples include: [28] block local variables (variables that are local to the block in which they are declared) an additional lambda syntax: f =-> (a, b) {puts a + b} an additional Hash literal syntax using colons for symbol keys: {symbol_key: "value"} == {:symbol_key => "value"}
The most frequently used general-purpose implementation of an associative array is with a hash table: an array combined with a hash function that separates each key into a separate "bucket" of the array. The basic idea behind a hash table is that accessing an element of an array via its index is a simple, constant-time operation.
The hash function translates the key associated with each datum or record into a hash code, which is used to index the hash table. When an item is to be added to the table, the hash code may index an empty slot (also called a bucket), in which case the item is added to the table there.
Cuckoo hashing is a form of open addressing in which each non-empty cell of a hash table contains a key or key–value pair.A hash function is used to determine the location for each key, and its presence in the table (or the value associated with it) can be found by examining that cell of the table.