Unary Negative and Positive
As unary operations have only one operand they are evaluated before other operations containing them. Here is an example using negation:
- 3 − −2
Here the first '−' represents the binary subtraction operation, while the second '−' represents the unary negation of the 2. Therefore, the expression is equal to:
- 3 − (−2) = 5
Technically there is also a unary positive but it is not needed since we assume a value to be positive:
- (+2) = 2
Unary positive does not change the sign of a negative operation:
- (+(−2)) = (−2)
In this case a unary negative is needed to change the sign:
- (−(−2)) = (+2)
Unary operators (called "monadic" in APL) are also used in programming languages.
Read more about this topic: Unary Operation
Famous quotes containing the words negative and/or positive:
“The idealist’s programme of political or economic reform may be impracticable, absurd, demonstrably ridiculous; but it can never be successfully opposed merely by pointing out that this is the case. A negative opposition cannot be wholly effectual: there must be a competing idealism; something must be offered that is not only less objectionable but more desirable.”
—Charles Horton Cooley (1864–1929)
“The most positive men are the most credulous.”
—Jonathan Swift (1667–1745)