In some
programming languages,
eval
is a
function which evaluates a string as though it were an
expression and returns a
result; in others, it executes multiple lines of code as though they had been included instead of the line including the
eval
. The input to
eval
is not necessarily a string; it may be structured representation of code, such as an
abstract syntax tree (like
Lisp forms), or of special type such as
code
(as in Python). The analog for a
statement is
exec
, which executes a string (or code in other format) as if it were a statement; in some languages, such as Python, both are present, while in other languages only one of either
eval
or
exec
is.