Question: I am familiar of how to get ajax to go to a php page an execute a series of things and then return json data. However is it possible to call a specific function which resides in a given page?

Basically what I want is to reduce the number of files in a project. So I can put a lot of common functions in one page and then just call whatever the function that I want at the moment.

Answer: 
**You cannot call a PHP function directly from an AJAX request, but you can do this instead:**

```
<? php 
    function test($data){
        return $data+1;
    }

    if (isset($_POST['callFunc1'])) {
        echo test($_POST['callFunc1']);
    }
?>
<script>
    $.ajax({
        url: 'myFunctions.php',
        type: 'post',
        data: { "callFunc1": "1"},
        success: function(response) { console.log(response); }
    });
</script>

```
If I understand correctly, yes you can.
Put all your functions in one php file and have the ajax pass as a parameter which one you want to call. Then with a switch or if structure, execute the one you want.