IE problem with JQuery

Question

I am working on page layout in SharePoint 2016 on prem, and using jquery for some simple manipulation.

I need to load my .js - file in edit mode panel only. I reference the .js-file like this in the page layout:

<PublishingWebControls:EditModePanel runat="server">
        <!-- Styles for edit mode only-->           
        <script type="text/javascript" src='http://absolutepath/Style%20Library/myScript.js'></script>
    </PublishingWebControls:EditModePanel>

This is my jQuery code:

$(document).ready(function() {
$('input[title="Til"]').click (function () {
    alert('clicked');

    $("input[Title='Fra']").attr("disabled", "");

    var checkbox = $("input[id *= 'checkboxrutine']");

    for(let i = 0; i < checkbox.length; i++)
    {
         $('input[id="' + checkbox[i].id + '"]').attr("checked", "checked"); 
    }    
}); // end of click
}); // end of documen tready function

It works in Chrome and FireFox, but only not in IE. I have done iisreset and published the .js - file, and clicked ctrl+f5 hundred times . I cannot even find the script in IE by using the developer tools (f12).

Am I doing anything wrong here with regards to referncing the file ? Or is there any issues with the jQuery code that does not work in IE ? What can I do to make this work in IE ? Please advice.

Answer 1

I think your issue is using for(let i = 0 syntax.

It has not worked very well in IE < edge: https://stackoverflow.com/questions/39159669/let-statement-in-loop-doesnt-work-as-expected-in-ie