How can you use php in a javascript function [duplicate]

You can't run PHP code with Javascript. When the user recieves the page, the server will have evaluated and run all PHP code, and taken it out. So for example, this will work:

alert( <?php echo "\"Hello\""; ?> );

Because server will have evaluated it to this:

alert("Hello");

However, you can't perform any operations in PHP with it.

This:

function Inc(){<?php$num = 2;echo $num;?>}

Will simply have been evaluated to this:

function Inc(){    2}

If you wan't to call a PHP script, you'll have to call a different page which returns a value from a set of parameters.

This, for example, will work:

script.php

$num = $_POST["num"];echo $num * 2;

Javascript(jQuery) (on another page):

$.post('script.php', { num: 5 }, function(result) {    alert(result); });

This should alert 10.

Good luck!

Edit: Just incrementing a number on the page can be done easily in jQuery like this: http://jsfiddle.net/puVPc/

I think you're confusing server code with client code.

JavaScript runs on the client after it has received data from the server (like a webpage).

PHP runs on the server before it sends the data.

So there are two ways with interacting with JavaScript with php.

Like above, you can generate javascript with php in the same fashion you generate HTML with php.

Or you can use an AJAX request from javascript to interact with the server. The server can respond with data and the javascript can receive that and do something with it.

I'd recommend going back to the basics and studying how HTTP works in the server-client relationship. Then study the concept of server side languages and client side languages.

Then take a tutorial with ajax, and you will start getting the concept.

Good luck, google is your friend.

you use script in php..

<?php        $num = 1;        echo $num;    echo '<input type="button"           name="lol"            value="Click to increment"           onclick="Inc()" />    <br>    <script>        function Inc()        {';            $num = 2;            echo $num;        echo '}    </script>';?>