Expressions
In most languages, statements contrast with expressions in that statements do not return results and are executed solely for their side effects, while expressions always return a result and often do not have side effects at all. Among imperative programming languages, Algol 68 is one of the few in which a statement can return a result. In languages which mix imperative and functional styles, such as the Lisp family, the distinction between expressions and statements is not made: even expressions executed in sequential contexts solely for their side effects and whose return values are not used are considered 'expressions'. In purely functional programming, there are no statements; everything is an expression.
Read more about this topic: Statement (computer Science)
Famous quotes containing the word expressions:
“Its idea of “production value” is spending a million dollars dressing up a story that any good writer would throw away. Its vision of the rewarding movie is a vehicle for some glamour-puss with two expressions and eighteen changes of costume, or for some male idol of the muddled millions with a permanent hangover, six worn-out acting tricks, the build of a lifeguard, and the mentality of a chicken-strangler.”
—Raymond Chandler (1888–1959)
“Compare the history of the novel to that of rock ‘n’ roll. Both started out a minority taste, became a mass taste, and then splintered into several subgenres. Both have been the typical cultural expressions of classes and epochs. Both started out aggressively fighting for their share of attention, novels attacking the drama, the tract, and the poem, rock attacking jazz and pop and rolling over classical music.”
—W. T. Lhamon, U.S. educator, critic. “Material Differences,” Deliberate Speed: The Origins of a Cultural Style in the American 1950s, Smithsonian (1990)
“We ought to celebrate this hour by expressions of manly joy. Not thanks, not prayer seem quite the highest or truest name for our communication with the infinite,—but glad and conspiring reception,—reception that becomes giving in its turn, as the receiver is only the All-Giver in part and infancy.”
—Ralph Waldo Emerson (1803–1882)