Unary_operator

Unary operation

Unary operation

Mathematical operation with only one operand

In mathematics, a unary operation is an operation with only one operand, i.e. a single input.[1] This is in contrast to binary operations, which use two operands.[2] An example is any function f : A → A, where A is a set. The function f is a unary operation on A.

Common notations are prefix notation (e.g. ¬, −), postfix notation (e.g. factorial n!), functional notation (e.g. sin x or sin(x)), and superscripts (e.g. transpose AT). Other notations exist as well, for example, in the case of the square root, a horizontal bar extending the square root sign over the argument can indicate the extent of the argument.

Examples

Absolute value

Obtaining the absolute value of a number is a unary operation. This function is defined as where is the absolute value of .

Negation

This is used to find the negative value of a single number. Here are some examples:

Factorial

For any positive integer n, the product of the integers less than or equal to n is a unary operation called factorial. In the context of complex numbers, the gamma function is an unary operation extension of factorial.

Trigonometry

In trigonometry, the trigonometric functions, such as , , and , can be seen as unary operations. This is because it is possible to provide only one term as input for these functions and retrieve a result. By contrast, binary operations, such as addition, require two different terms to compute a result.

Examples from programming languages

Below is a table summarizing common unary operators along with their symbols, description, and examples:[3]

More information Operator, Symbol ...

JavaScript

In JavaScript, these operators are unary:[4]

C family of languages

In the C family of languages, the following operators are unary:[5][6]

Unix shell (Bash)

In the Unix shell (Bash/Bourne Shell), e.g., the following operators are unary:[7][8]

  • Pre and Post-Increment: ++$x, $x++
  • Pre and Post-Decrement: --$x, $x--
  • Positive: +$x
  • Negative: -$x
  • Logical negation: !$x
  • Simple expansion: $x
  • Complex expansion: ${#x}

PowerShell

In the PowerShell, the following operators are unary:[9]

  • Increment: ++$x, $x++
  • Decrement: --$x, $x--
  • Positive: +$x
  • Negative: -$x
  • Logical negation: !$x
  • Invoke in current scope: .$x
  • Invoke in new scope: &$x
  • Cast: [type-name] cast-expression
  • Cast: +$x
  • Array: ,$array

See also

References

  1. [1]
    Weisstein, Eric W. "Unary Operation". mathworld.wolfram.com. Retrieved 2020-07-29.
  2. [2]
    Weisstein, Eric W. "Binary Operation". mathworld.wolfram.com. Retrieved 2020-07-29.
  3. [3]
    "Unary Operators in Programming". GeeksforGeeks. 20 March 2024. Retrieved 24 April 2024.
  4. [4]
    "Unary Operators".
  5. [5]
    "5. Expressions and Operators". C/C++ Language Reference. Version 6.0. p. 109. Archived from the original on 2012-10-16.
  6. [6]
    "Unary Operators - C Tutorials - Sanfoundry". www.sanfoundry.com.
  7. [7]
    "Shell Arithmetic (Bash Reference Manual)". www.gnu.org. GNU Operating System. Retrieved 24 April 2024.
  8. [8]
    Miran, Mohammad Shah (26 October 2023). "Unary Operators in Bash". LinuxSimply. Retrieved 24 April 2024.
  9. [9]
    "Expressions - PowerShell". learn.microsoft.com. Microsoft. 3 September 2021. Retrieved 23 April 2024.
Share this article:

This article uses material from the Wikipedia article Unary_operator, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.