php run javascript code

Question

is it possible to run some javascript expression? for example echo eval("Math.sqrt('25')");

Answer 1

In normal situations :

• PHP runs on the server
• and, then, Javascript is run on the client, in the browser.

So, no, it's not quite possible to have PHP execute some Javascript code on the server.

But there is at least on PHP extension that embed (or wrap arround) a Javascript engine, and, as a consequence, allows one to execute Javascript on the server, from PHP.

The extension I'm thinking about is the spidermonkey one : installing and enabling it on your server will allow you to execute Javascript code, on the server, from PHP.

Of course, like any other PHP extension, you'll need to be admin of your server, in order to install it -- and this one is never installed by default, as it answers a very specific need.

About this extension, I have never seen it used in real situations, and there are not many people who tried it... here are two articles you might want to read :

• Using JavaScript in PHP with PECL and SpiderMonkey
• and SpiderMonkey : Exécuter du Javascript c?té serveur, depuis PHP (this one is in french, and on my own blog)