expression

programming Any piece of program code in a high-levellanguage which, when (if) its execution terminates, returns a

value. In most programming languages, expressions consist of

constants, variables, operators, functions, and parentheses.

The operators and functions may be built-in or user defined.

Languages differ on how expressions of different types may

be combined - with some combination of explicit casts and

implicit coercions.

The syntax of expressions generally follows conventional

mathematical notation, though some languages such as Lisp or

Forth have their own idiosyncratic syntax.

(2001-05-14)