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!

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 DOM Scripting By Example Editing and Filtering Names States of the Application

Tyler McDonald
.a{fill-rule:evenodd;}techdegree seal-36
Tyler McDonald
Full Stack JavaScript Techdegree Graduate 16,700 Points

Declaring constants in the edit/remove buttons event handler

I am wondering if there would be any potential reason why I would not want to declare the variables in the event handler outside of both if statements, rather than within the parent if statement like Guil does in the video. This is how I did it:

ul.addEventListener('click', (e) => {
    const button = e.target;
    const li = button.parentNode;
    const ul = li.parentNode;
    if (button.tagName === 'BUTTON') {
        if (button.textContent === 'remove') {
        } else if (button.textContent === 'edit') {
            li.type = 'input';

Thanks for the advice!

1 Answer

Steven Parker
Steven Parker
228,001 Points

There's no functional difference; but when placed outside the "if", the variables will always be created even if the event occurs for something other than a button.

When located as shown on the video, the assignments will be efficiently skipped in all cases where the event is for some other element. And as a minor code readability issue, it seems a bit awkward to assign the element to a variable named "button" when it is not a button.