This article needs additional citations for
verification. (March 2010) |
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.
Obtaining the absolute value of a number is a unary operation. This function is defined as where is the absolute value of .
This is used to find the negative value of a single number. Here are some examples:
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.
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.
Below is a table summarizing common unary operators along with their symbols, description, and examples: [3]
Operator | Symbol | Description | Example |
---|---|---|---|
Increment | ++ |
Increases the value of a variable by 1 | x = 2; ++x; // x is now 3
|
Decrement | −- |
Decreases the value of a variable by 1 | y = 10; --y; // y is now 9
|
Unary Plus | + |
Indicates a positive value | a = -5; b = +a; // b is -5
|
Unary Minus | - |
Indicates a negative value | c = 4; d = -c; // d is -4
|
Logical NOT | ! |
Negates the truth value of a boolean expression | flag = true; result = !flag; // result is false
|
Bitwise NOT | ~ |
Bitwise negation, flips the bits of an integer | num = 5; result = ~num; // result is -6
|
In JavaScript, these operators are unary: [4]
++x
, x++
--x
, x--
+x
-x
~x
!x
In the C family of languages, the following operators are unary: [5] [6]
++x
, x++
--x
, x--
&x
*x
+x
-x
~x
!x
sizeof x, sizeof(type-name)
(type-name) cast-expression
In the Unix shell ( Bash/ Bourne Shell), e.g., the following operators are unary: [7] [8]
++$x
, $x++
--$x
, $x--
+$x
-$x
!$x
$x
${#x}
In the PowerShell, the following operators are unary: [9]
++$x
, $x++
--$x
, $x--
+$x
-$x
!$x
.$x
&$x
type-name] cast-expression
+$x
,$array
This article needs additional citations for
verification. (March 2010) |
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.
Obtaining the absolute value of a number is a unary operation. This function is defined as where is the absolute value of .
This is used to find the negative value of a single number. Here are some examples:
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.
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.
Below is a table summarizing common unary operators along with their symbols, description, and examples: [3]
Operator | Symbol | Description | Example |
---|---|---|---|
Increment | ++ |
Increases the value of a variable by 1 | x = 2; ++x; // x is now 3
|
Decrement | −- |
Decreases the value of a variable by 1 | y = 10; --y; // y is now 9
|
Unary Plus | + |
Indicates a positive value | a = -5; b = +a; // b is -5
|
Unary Minus | - |
Indicates a negative value | c = 4; d = -c; // d is -4
|
Logical NOT | ! |
Negates the truth value of a boolean expression | flag = true; result = !flag; // result is false
|
Bitwise NOT | ~ |
Bitwise negation, flips the bits of an integer | num = 5; result = ~num; // result is -6
|
In JavaScript, these operators are unary: [4]
++x
, x++
--x
, x--
+x
-x
~x
!x
In the C family of languages, the following operators are unary: [5] [6]
++x
, x++
--x
, x--
&x
*x
+x
-x
~x
!x
sizeof x, sizeof(type-name)
(type-name) cast-expression
In the Unix shell ( Bash/ Bourne Shell), e.g., the following operators are unary: [7] [8]
++$x
, $x++
--$x
, $x--
+$x
-$x
!$x
$x
${#x}
In the PowerShell, the following operators are unary: [9]
++$x
, $x++
--$x
, $x--
+$x
-$x
!$x
.$x
&$x
type-name] cast-expression
+$x
,$array