Course: JavaScript

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  1. Foundation

  2. Numbers

  3. Strings

  4. Conditions

  5. Loops

  6. Arrays

  7. Functions

  8. Objects

  9. Exceptions

  10. HTML DOM

  11. CSSOM

  12. Events

  13. Drag and Drop

  14. opt Touch Events

  15. Misc

  16. Project: Analog Clock

JavaScript Scroll Event Quiz

Quiz 27 7 questions

Prerequisites for the quiz

  1. JavaScript Scroll Event

Are you ready?

7 questions to solve

Instructions
  1. This quiz goes to full-screen once you press the Start button.
  2. At the end of the quiz, you are able to review all the questions that you answered wrong and see their explanations.
Which of the properties pageXOffset and scrollX is older than the other?
pageXOffset is an older property if we compare it to scrollX. Both do exactly the same thing i.e return the vertical scroll offset of the HTML document. For more info, refer to JavaScript Scroll Event.
The pageXOffset property is available on all element nodes. True or false?
pageXOffset is only available on the window object. See more details at JavaScript Scroll Event.
How to get the vertical scroll offset of a given element?
For an element, its vertical scroll offset can be determined by querying the scrollTop property. However for the case of window, this thing is done using scrollY or pageYOffset.
Is there any way to programatically change the scroll offset of an element. If yes, then what is it?
The scroll() method is one of the ways to programatically change the vertical scroll offset of an element. This goes with choice C). The other ways are scrollTo(), scrollBy() and scrollTop.
The scroll() and scrollTo() methods do the same thing. True or false?
scroll() and scrollTo() do exactly the same thing. It's just that scroll() is a bit older compared to scrollTo().
Is the following code correct to navigate the HTML document to a vertical scroll offset of 10px?
window.scrollY = 10;
Assigning a value to the property scrollY has no effect. This means that the code above is technically not correct for the given task. See more at JavaScript Scroll Event.
What does it mean to debounce the onscroll handler?
Debouncing means to wait for a certain amount of time before firing a function from within the handler of the scroll event. This goes with choice B). See more details at JavaScript Scroll Event - Debouncing.