link-active.js

function stripTrailingSlash(str) {
    if (str.substr(-1) == '/') {
        return str.substr(0, str.length - 1);
    }
    return str;
}

var url = window.location.pathname;
var activePage = stripTrailingSlash(url);

var array = activePage.split('/');
var page = '/' + array[1];

$('.nav li a').each(function () {
    var currentPage = stripTrailingSlash($(this).attr('href'));

    if (page == currentPage) {
        $(this).parent().addClass('active');
    }
});