What (who) is hash character - definition
TYPOGRAPHIC ASCII SYMBOL "#"
Octothorpe; Hash sign; Hash symbol; Pound key; Octathorpe; Octalthorpe; Anoctothorpe; ﹟; Octatherp; ＃; Number key; Octathorp; Octothorp; Hash character; Number Sign; Number symbol; U+0023; Octotherp; Hash mark (character); Hash (character); ASCII 35; \x23; Number signs; # Hashtag symbol; Hashtag sign
![Detail of a telephone keypad displaying the [[Viewdata]] square](https://commons.wikimedia.org/wiki/Special:FilePath/Detail-Tastatur-FeTAp-751-1982.JPG?width=200 "Detail of a telephone keypad displaying the [[Viewdata]] square")
![libra pondo]]'' ("pound weight")](https://commons.wikimedia.org/wiki/Special:FilePath/Pfund.svg?width=200 "libra pondo]]'' (\"pound weight\")")
hash character
<character> "#", ASCII character 35.
Common names: number sign; pound; pound sign; hash; sharp;
crunch; hex; INTERCAL: mesh. Rare: grid; crosshatch;
octothorpe; flash; ITU-T: square, pig-pen; tictactoe;
scratchmark; thud; thump; splat.
The pronunciation of "#" as "pound" is common in the US but a
bad idea; Commonwealth Hackish has its own, rather more
apposite use of "pound sign" (confusingly, on British
keyboards the pound graphic happens to replace "#"; thus
Britishers sometimes call "#" on a US-ASCII keyboard "pound",
compounding the American error). The US usage derives from an
old-fashioned commercial practice of using a "#" suffix to tag
pound weights on bills of lading. The character is usually
pronounced "hash" outside the US.
The name "octothorpe" was made up by a Bell Labs supervisor,
Don Macpherson.
{Octothorpe story
(http://sigtel.com/tel_tech_octothorpe.html) }.
(2003-07-05)
hash table
![This graph compares the average number of CPU cache misses required to look up elements in large hash tables (far exceeding size of the cache) with chaining and linear probing. Linear probing performs better due to better [[locality of reference]], though as the table gets full, its performance degrades drastically.](https://commons.wikimedia.org/wiki/Special:FilePath/Hash table average insertion time.png?width=200 "This graph compares the average number of CPU cache misses required to look up elements in large hash tables (far exceeding size of the cache) with chaining and linear probing. Linear probing performs better due to better [[locality of reference]], though as the table gets full, its performance degrades drastically.")
ASSOCIATES DATA VALUES WITH KEY VALUES - A LOOKUP TABLE
Hashtable; Hash-table; Hash tables; Hash map; Rehash; Hashmap; Open hashing; Scatter storage; Address-calculation sort; Hash Table; Chaining hash table; Separate chaining; Direct chaining; Collision resolution scheme; External chaining; Load factor (computer science); Hash-Based Indexes; Hash table collisions; Hash table collision; Array hash table; Dynamic-sized hash table; Collision resolution in hash tables
number sign
<character> hash.
Wikipedia
Number sign
The symbol # is known variously in English-speaking regions as the number sign, hash, or pound sign. The symbol has historically been used for a wide range of purposes including the designation of an ordinal number and as a ligatured abbreviation for pounds avoirdupois – having been derived from the now-rare ℔.
Since 2007, widespread usage of the symbol to introduce metadata tags on social media platforms has led to such tags being known as "hashtags", and from that, the symbol itself is sometimes called a hashtag.
The symbol is distinguished from similar symbols by its combination of level horizontal strokes and right-tilting vertical strokes.
