How to load an external js file as plain text and assign to variable as a string

Try to use Ajax.get() :

var script;
$.get('script.js', function(data) {
  script = data;
});

for Ajax.get() it will work inside your domain, you can't call external domains, if your application requires loading external JS file then my guess is that you have to use PHP or another server-side language as:

var script;
$.get('getScript.php', {url: "http://test.com/script.js"}function(data) {
  script = data;
});

in getScript.php you can use CURL or file_get_contents

Note that $.get() and $.post() and $.ajax() are all the same thing.

$.get and $.post are just shorthand versions of $.ajax() that come with presets (obviously, type: "GET" and type:"POST" for one...). I prefer using $.ajax because the format can be more structured, and therefore easier to learn/use.

Javascript/jQuery would look something like this:

<script type="text/javascript">

    $(document).ready(function() {
        $.ajax({
            type: "POST",
            url: "loadmyfile.php",
            data: 'filename=js/myscript.js',
            success: function(whatigot) {
                //alert('Server-side response: ' + whatigot);
                $('#myhiddentext').val(whatigot);
            } //END success fn
        }); //END $.ajax
    }); //END $(document).ready()

</script>

Important: Note that you would need to do all the post-AJAX processing inside the success function. See this link for some simple AJAX examples.

Note that you can send data across to the PHP file by specifying a data: parameter in the AJAX code block. Optionally, you can leave out that line and simply hard-code the filename into the PHP file.

The text of the retrieved js file comes back into the AJAX success function (from the PHP file) as a string in the variable specified as the function param (in this case, called 'whatigot'). Do what you want with it; I have stored it inside a hidden <input> control in case you wish to retrieve the text OUTSIDE the AJAX success function.

PHP would look something like this:

loadmyfile.php

<?php
    $fn = $_POST['filename'];

    $thefile = file_get_contents($fn);
    echo $thefile;

References: PHP file_get_contents