Vertical bar

Vertical Bar

The vertical bar, also known as the pipe symbol, is a character with a variety of uses in computing, mathematics, and other fields. It is represented by the symbol `|` and is commonly found on computer keyboards, often above the backslash `\` key.

Uses in Computing

In computing, the vertical bar is a versatile character used in several contexts:

Command Line Interfaces

In many command line interfaces, such as Unix-based systems, the vertical bar is used as a pipe operator. It allows the output of one command to be used as the input to another command. For example:

``` ls -l | grep "txt" ```

In this example, the output of the `ls -l` command, which lists files in long format, is piped into the `grep` command to filter for files containing "txt" in their names.

Programming Languages

In programming languages, the vertical bar can serve different purposes:

• Logical OR Operator: In languages like C, C++, and Java, the double vertical bar `||` is used as a logical OR operator in conditional statements.
• Bitwise OR Operator: A single vertical bar `|` is used as a bitwise OR operator, which performs a binary OR operation on two numbers.

Regular Expressions

In regular expressions, the vertical bar is used as an alternation operator, allowing for the matching of one pattern or another. For example, the pattern `cat|dog` will match either "cat" or "dog".

Uses in Mathematics

In mathematics, the vertical bar has several applications:

• Absolute Value: The vertical bar is used to denote the absolute value of a number. For example, `|x|` represents the absolute value of `x`.
• Divisibility: In number theory, the vertical bar is used to indicate divisibility. For example, `a | b` means that `a` divides `b` without a remainder.
• Set Notation: In set theory, the vertical bar is used in set-builder notation to separate the variable from the condition. For example, `{ x | x > 0 }` represents the set of all `x` such that `x` is greater than 0.

Uses in Typography

In typography, the vertical bar is used as a separator or delimiter. It can be used to separate items in a list or to denote alternatives in text.

Also see

• Pipe (computing)
• Logical OR
• Bitwise operation
• Regular expression
• Absolute value
• Set-builder notation

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