Editing Eval (section)

{{short description|Function in a programming language, which evaluates a string}}
{{redirects|Evaluation (computer science)|other uses|Evaluation (disambiguation)}}
{{lowercase}}
{{Use mdy dates|date=April 2025}}
{{Use American English|date=April 2025}}
In some [[programming language]]s, '''<code>eval</code>''' , short for [[wiktionary:evaluate|evaluate]], is a [[subroutine|function]] which evaluates a string as though it were an [[expression (programming)|expression]] in the language, and returns a [[return value|result]]; in others, it executes multiple lines of code as though they had been included instead of the line including the <code>eval</code>. The input to <code>eval</code> is not necessarily a string; it may be structured representation of code, such as an [[abstract syntax tree]] (like [[Lisp (programming language)|Lisp]] forms), or of special type such as <code>code</code> (as in Python). The analog for a [[Statement (computer science)|statement]] is [[Exec (system call)|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 <code>eval</code> or <code>exec</code> is.