My program doesn't print to the browser window, could someone help?

Hi there Oneeb!

Bug was in function buildList. In for loop after comparing operation

j <= arr.length()

you were trying to invoke length() method from array object. But it is a property. Removing parentheses solved the problem.

Another small problem appears after whole list of right and worng answers were displayed. Undefined string, each time in right or wrong section. To remove this small problem you need to first

change comparing operator from <= to < in for loop(buildList function).

j < arr.length

And after that add check if array that comes to the function is not empty. This will also helps you to avoid new visual bugs ;)

Below you can find improved buildList method.

function buildList(arr) {
    if (arr.length) {
        var listHTML = "<ol>";
        for (var j = 0; j < arr.length; j += 1) {
            listHTML += "<li>" + arr[j] + "</li>";
        }
        listHTML += "</ol>";
        return listHTML;
    } else return "Nothing to show";
}

Best regards!