I’m trying to set onTop state to true if the user has scrolled to the top and false otherwise. I tried the following. The above example doesn’t work but throws no error either. Note that I added an arrow and braces to the second parameter function. The above example works as intended. Can anyone explain why? Thanks very much! Answer
Tag: addeventlistener
How can I call function on event listener to change class using map method
I have two buttons, button 1 and button 2 of different classes with different color and background color. When mouseover button 1 I want the color and background color to change to the color and background color of button 2 and and the color and background color of button 2 to change to the color and background color of button
Understanding debounce function logic flow, particularly for Event object – where does (…args) get it’s values from?
I’m working through a Javascript course and am working with the following code. I understand almost all of it but I’m struggling with following and understanding the logic flow through the code, particularly for the event objects and I want to make sure I’m super clear on this before continuing. Almost the exact same question has been asked here by
Basic keyboard functionality for movement of object
I am unable to figure out what is wrong with my code. I have another example I was able to get to work but it didn’t use constructor objects and this one does. That’s about the only different I can think of. I’ve tweaked it in many ways but no luck. Please help me understand why it isn’t working. Answer
Dynamically create a click event based on an array and change format of the clicked element
I have 5 div tags each with its unique class name and two of them have the same class except the second one has an extra class (i.e. “.cls2” and “.cls2.a”). I have put these classes in an array and I am trying to create a click event where the clicked element containing the class from the array will do
why does the event listener in this throttling function behave like that?
While I was learning about throttling in javascript, I came upon an event-listener behavior that I can’t explain. Here is a simple throttling function. I have two questions. Why does let prev = 0; only get called once? i.e why doesn’t prev get reset to 0 every time the function is called? I have also noticed that let prev =
Uncaught TypeError: Cannot read property ‘addEventListener’ of null at app.js:2 with checkbox [closed]
Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers. This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers. Closed 2 years ago. Improve this question
Can’t add an event listener to an element from an API
I am building a trivia webapp using an API and i want to add an event listener to the button with the correct answer so that when the user clicks it it will display a message saying they’re right and it’ll get a new question. Here’s how the code looks: It tells me that the AddEventListener is not a function,
What am doing wrong in here?
Input value always gets into if condition first even am parsing it to parseInt() and when page refreshed with a number it gets into else condition, like its not registering the inputValue at first place, also if i add a submit event rather an click one event doesnt fires up. Answer You’re recording the value of the input on page
why my last.addEventListener(“click”,nextLevel) not working?
https://codepen.io/demi-chen/pen/RwGPgxv I try to find the lastElementChild in the first div. It does show …… after I use console.log to check. why the addEventListener not working. I click the lastElementChild smile.png face but it’s not working. if function nextLevel() is working. the left&right side should add more smile.png. Tks! Answer its quite a simple fix really change your nextlevel to