Vertical bar

The vertical bar (English vertical bar, in programmer jargon often Pipe) is used primarily in the computer and mathematics. The German term for the character in the IT area is concatenation character.

The character is either represented as a continuous vertical bar (| |) or in the middle of interrupted ().

On PCs with the operating systems DOS, Windows, and Linux, it is produced in a German keyboard layout, the key combination Alt Gr <. On a Mac, you create it with the key combination ⌥ 7. The Swiss German keyboard layout provides the key combination Alt Gr 7 and for the unbroken line Alt Gr 1 broken bar; However, Windows is inversely related to the labeling of the keyboards, which can lead to confusion.

Use

Mathematics

• The simple vertical bar represents the relation " divides " between integers
• The conditional probability in the probability theory
• The restriction of the domain of a given function, if two sets have and a function definition area is referred to as the function that is to coincide with or otherwise undefined.
• The evaluation function at one place.
• The difference between two function values ​​at two points, such as the integral calculus:
• " With the property " or " for the following applies: " in the intensional notation of quantities:

• The Shefferschen line in the logic

• A pair of simple vertical lines ( such as braces ) denotes the absolute value of a number
• The determinant of a matrix
• The cardinality of a set

• The double vertical bar denotes the parallelism:

• A pair of double vertical lines (such as brackets) refers to a standard

Physics

• In the Dirac notation in physics is a matrix element

Programming

• In shells, a vertical line called a pipe. With Pipes can be input and output power of two programs to concatenate. (Eg: ls | more)
• Two vertical lines one after the other call in many programming languages ​​(eg C, Perl ) a logical or and a simple vertical line the bitwise-or
• Two vertical lines denote consecutively in different programming languages ​​(eg Rexx ) the concatenation of two strings
• For some search engines, such as Google, the vertical bar - set with no space between searches - replace the "OR" operator

Others

• In encyclopedias and dictionaries, such as the dictionary, and referred to the vertical bar possible separation points of a word; alternatively, a center is sometimes used
• In the International Phonetic Alphabet (IPA ) and Khoisan languages ​​shows that the vertical bar the dental click
• In the text of Sciences of the vertical bar character is often used to mark a page break

Coding

The vertical lines are defined as follows and codes:

In the ASCII character set in its current version is the vertical bar, but does not contain the interrupted line. However, this occurs in the same old fonts from IBM. However, already the ASCII extensions to ISO 6937 and ISO 8859-1 included (also known as Latin-1 ) in 1986 both line variants. Almost all modern computers with Latin fonts use the ISO-8859 variant or the Unicode standard and can therefore be easily processed and are both characters.

For the two variants of the vertical bar ( continuous and interrupted ), there was originally a reason: With the older fonts, there were those which the vertical line confusingly identical represented as the lowercase letter l ( " ell " ) and the uppercase letter I ( " large i "). In demanding documents thus occurred three characters with an ( almost) equal representation.

• The dashed vertical line to let avoid this problem ( misunderstanding of the text ).
• In the representation with descender of today we could easily to continuous vertical line (or vice versa) back. Obviously the falls the computer companies difficult: Microsoft keyboards contain only the broken vertical line.
• Google keyboards contain only the continuous vertical line.