Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Using For Loops with Arrays

Posted by mk37
mk37
10,271 Points

why does this code not work?

    function printD(html) {
            return document.write(html);
    };


    var alphabetsZ = ["A", "B", "C"];


    function olArr(liArr) {
        var listz = "<ol>";
        for (var i = 0; i < liArr.length; i += 1) {
            listz += "<li>" + liArr[i] + "</li>";
        };
        listz += "</ol>";
    };

    printD( olArr( alphabetsZ ) );
// output -  undefined

i know the code is fine in general and if i put printD(listz); within the function and call the function as normal it will work fine. but trying a different way that i did, to me my way should work too. i know the problem is mainly :

    printD( olArr( alphabetsZ ) );

it comes off as undefined even though the code looks fine to me too! my guess is you cannot use function within a function?

1 Answer

Elijah Quesada
.a{fill-rule:evenodd;}techdegree seal-36
Elijah Quesada
Front End Web Development Techdegree Graduate 32,965 Points

You need to add a return statement. A function will return undefined by default. In order to return a value you need to add the return statement. 

    function printD(html) {
            return document.write(html);
    };


    var alphabetsZ = ["A", "B", "C"];


    function olArr(liArr) {
        var listz = "<ol>";
        for (var i = 0; i < liArr.length; i += 1) {
            listz += "<li>" + liArr[i] + "</li>";
        };
      return  listz += "</ol>";
    };

    printD( olArr( alphabetsZ ) );
mk37
mk37
10,271 Points

omg i feel so stupid that i forgot to add a return. thanks for the help Elijah