Editing Eval (section)

=== ECMAScript ===
==== JavaScript ====
In [[JavaScript]], <code>eval</code> is something of a hybrid between an expression evaluator and a statement executor. It returns the result of the last expression evaluated.

Example as an expression evaluator:
<syntaxhighlight lang="javascript">
foo = 2;
alert(eval('foo + 2'));
</syntaxhighlight>

Example as a statement executor:
<syntaxhighlight lang="javascript">
foo = 2;
eval('foo = foo + 2;alert(foo);');
</syntaxhighlight>

One use of JavaScript's <code>eval</code> is to parse [[JSON]] text, perhaps as part of an [[Ajax (programming)|Ajax]] framework.  However, modern browsers provide <code>JSON.parse</code> as a more secure alternative for this task.

==== ActionScript ====

In [[ActionScript]] (Flash's programming language), <code>eval</code> cannot be used to evaluate arbitrary expressions. According to the Flash 8 documentation, its usage is limited to expressions which represent "the name of a variable, property, object, or movie clip to retrieve. This parameter can be either a String or a direct reference to the object instance."<ref>{{cite web
|url = http://livedocs.macromedia.com/flash/8/index.html
|archive-url = https://web.archive.org/web/20061010123451/http://livedocs.macromedia.com/flash/8/index.html
|url-status = dead
|archive-date = October 10, 2006
|title = Flash 8 LiveDocs
|date = October 10, 2006}}</ref>

ActionScript 3 does not support eval.

The ActionScript 3 Eval Library<ref>[http://eval.hurlant.com ActionScript 3 Eval Library]</ref> and the D.eval API<ref>{{cite web |url=http://www.riaone.com/products/deval/ |title=The D.eval API |archive-url=https://web.archive.org/web/20130314012753/http://www.riaone.com/products/deval/ |archive-date=March 14, 2013 |url-status=dead}}</ref> were development projects to create equivalents to <code>eval</code> in ActionScript 3. Both have ended, as [[Adobe Flash Player]] has reached its [[End-of-life_product|end-of-life]].