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 negative cautions of science are never popular. If the experimentalist would not commit himself, the social philosopher, the preacher, and the pedagogue tried the harder to give a short- cut answer.”
—Margaret Mead (1901–1978)
“Regna regnis lupi, The State is a wolf unto the State. It is not a pessimistic lamentation like the old homo homini lupus [Man is a wolf to Man], but a positive creed and political ideal.”
—Johan Huizinga (1872–1945)