Include jQuery from another JavaScript file

Question

I am trying to include jQuery from a javascript file. I have tried the following, although it doesn't work.

var script = '<script type="text/javascript" src="http://code.jquery.com/jquery-1.9.1.min.js"></script>';
document.getElementsByTagName('head')[0].appendChild(script);

Answer 1

</script> closes the opening <script> block, even if it's in a string. I would do it this way:

(function() {
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = document.location.protocol + '//code.jquery.com/jquery-1.9.1.min.js';

    document.getElementsByTagName('head')[0].appendChild(script)
})();