jQuery script doesn't run in Internet Explorer (syntax error on line 1 char 1)

Question

I'm working on a responsive html mockup for a new project, and it contains some jquery scripts which run perfectly on every browser... Except for Internet Explorer (I'm currently testing it on IE9).

I naturally checked IE's javascript console, which gives me the following error message :

SCRIPT1002: Syntax error 
scripts.js, line 1 character 1

I have absolutely no idea where that could come from, as neither DreamWeaver or Komodo Edit detect anything wrong.

The mockup is online at the following address : http://zipion-live.be/cal-bw/

And here's the script which causes the error :

const visible = "visible";
const hidden = "hidden";
const open = "open";

$(document).ready(function(e) {
    $(".collapsible_container .links").hide();
    showHomeMenu();

    $("#home_link").click(showHomeMenu);

    $("#admin_link").click(showAdminMenu);

    $("#left_menu .links a").click(function() {
        $("#left_menu .links").slideUp("fast");
        $("#left_menu .collapsible_container").removeClass(open);
    });

    $("section .section_header").click(function() {
        var sectionContent = $(this).parent("section").children(".section_content");
        var sectionHeader = $(this);
        toggleSection(sectionHeader, sectionContent);
    });
});

function toggleSection(sectionHeader, sectionContent) {
    var isOpen = sectionHeader.hasClass(open);

    if (isOpen) {
        sectionContent.slideUp("slow", function() {
            sectionHeader.removeClass(open);
        });
    } else {
        sectionContent.slideDown("slow");
        sectionHeader.addClass(open);
    }
}

function setLeftMenuHeight() {
    var visibleChildren = $("#left_menu .collapsible").not(".hidden")

    if (visibleChildren.length > 8) {
        $("aside").removeClass("h100").addClass("h150");
    } else if (visibleChildren.length > 4) {
        $("aside").removeClass("h150").addClass("h100");
    } else {
        $("aside").removeClass("h100").removeClass("h150");
    }
}

function showHomeMenu() {
    $("#left_menu .admin").addClass("hidden");
    $("#left_menu .home").removeClass("hidden");
    $("#left_menu .admin h3 a").unbind("click");
    setLeftMenuHeight();

    $("#left_menu .home h3 a").click(function() {
        var current = $(this).parent("h3").parent(".collapsible_container").children(".links")
        animateMenu(current);
    });
}

function showAdminMenu() {
    $("#left_menu .home").addClass("hidden");
    $("#left_menu .admin").removeClass("hidden");
    $("#left_menu .home h3 a").unbind("click");
    setLeftMenuHeight();

    $("#left_menu .admin h3 a").click(function() {
        var current = $(this).parent("h3").parent(".collapsible_container").children(".links")
        animateMenu(current);
    });
}

function animateMenu(current) {
    var isVisible = current.hasClass(visible)       

    $("#left_menu .links").removeClass(visible);
    $("#left_menu .collapsible_container").removeClass(open);

    $.when($("#left_menu .links").slideUp("fast")).then(function() {
        if (!isVisible) {
            current.slideDown("fast");
            current.addClass(visible);
            current.parent(".collapsible_container").addClass(open);
        } else {
            current.parent(".collapsible_container").removeClass(open);
        }
    });
}

Any idea about this issue ? I'm quite new to jQuery and I'm totally clueless here...

P.S. : I'm using jquery in version 1.11.0, in case that's relevant.

Answer 1

Although const is a Javascript 1.5 standard feature it is not supported by modern versions of IE (6-10). Only gecko based browsers and Chrome support it.

Variables nowadays in javascript use var, not const to avoid this problem.

Change this :

const visible = "visible";
const hidden = "hidden";
const open = "open";

To this:

var visible = "visible";
var hidden = "hidden";
var open = "open";