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JavaScript

Lewis Mercer
Lewis Mercer
2,151 Points
Posted by Lewis Mercer
Lewis Mercer
2,151 Points

My solution deletes more buttons than meant to and gives error.

Here is my JS:

http://bit.ly/2YhMA6r

and HTML: http://bit.ly/2LnfIUB

And the error:

app.js:36 Uncaught TypeError: Cannot read property 'style' of undefined at showAllBtn (app.js:36) at hideButtons (app.js:47) at attachListItemButtons (app.js:30) at app.js:54

and a screenshot: https://pasteboard.co/IJIbJ0Z.png

Massive thanks to anyone who can spot my mistake!

1 Answer

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

I made some modifications and saved them to a workspace

1) Your inner loop in hideButtons() should run for the number of children in the list item.

This:

for(let j = 0; j<lis[i].length; j +=1){

should be this:

for(let j = 0; j<lis[i].children.length; j +=1){

2) You are calling hideButtons() every time you add buttons to a list item. This results in an error here:

lastItem.children[1].style.visibility = 'hidden';

since the last list item doesn't have children until it has buttons added (after all the other list items have theirs). So I removed hideButtons() from attachListItemButtons() and call it after all buttons have been added.

for (let i = 0; i < lis.length; i += 1) {
  attachListItemButtons(lis[i]);
}

hideButtons()

3) I changed these lines in hideButtons() to reference the current child elements of the list

listUl.firstElementChild.firstElementChild.style.visibility = 'hidden';
listUl.lastElementChild.children[1].style.visibility = 'hidden';
Lewis Mercer
Lewis Mercer
2,151 Points
Lewis Mercer
Lewis Mercer
2,151 Points

Wow, got work for a few days so not going to be able to give this a go quite yet but everything you have said makes perfect sense and I believe this will be really helpful. Thanks so much :)