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

Tyler McDonald
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Tyler McDonald
Full Stack JavaScript Techdegree Graduate 16,676 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') {
            ul.removeChild(li);
        } else if (button.textContent === 'edit') {
            li.type = 'input';
        }
    }

Thanks for the advice!

1 Answer

Steven Parker
Steven Parker
221,900 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.