Hello, I am a complete Javascript novice, however I need to solve a Javascript problem and I have completely no idea how to do it. I suspect the answer is very simple!
I have the following code (the script is taken from here). I want the elements with the class countup to ‘count up’ as per the script when they are in view on a website.
Could you please provide me with some assistance? Thanks in advance!
<html>
<body>
<div><span class="countup">200</span></div>
<div><span class="countup">200</span></div>
<div style="height:4000px;"></div>
<div><span class="countup">200</span></div>
<script id="rendered-js" >
// How long you want the animation to take, in ms
const animationDuration = 2000;
// Calculate how long each ‘frame’ should last if we want to update the animation 60 times per second
const frameDuration = 1000 / 60;
// Use that to calculate how many frames we need to complete the animation
const totalFrames = Math.round(animationDuration / frameDuration);
// An ease-out function that slows the count as it progresses
const easeOutQuad = t => t * (2 - t);
// The animation function, which takes an Element
const animateCountUp = el => {
let frame = 0;
const countTo = parseInt(el.innerHTML, 10);
// Start the animation running 60 times per second
const counter = setInterval(() => {
frame++;
// Calculate our progress as a value between 0 and 1
// Pass that value to our easing function to get our
// progress on a curve
const progress = easeOutQuad(frame / totalFrames);
// Use the progress value to calculate the current count
const currentCount = Math.round(countTo * progress);
// If the current count has changed, update the element
if (parseInt(el.innerHTML, 10) !== currentCount) {
el.innerHTML = currentCount;
}
// If we’ve reached our last frame, stop the animation
if (frame === totalFrames) {
clearInterval(counter);
}
}, frameDuration);
};
// Run the animation on all elements with a class of ‘countup’
const runAnimations = () => {
const countupEls = document.querySelectorAll('.countup');
countupEls.forEach(animateCountUp);
};
//# sourceURL=pen.js
</script>
</body>
</html>