creating fade out/in instead of display none/block

Question

I am trying to make the slides fade in and out instead of display none/block using JS. Is this going to need to be done using css or can i do it just in JS. Thanks

code:

var slideIndex = 1;
showSlides(slideIndex);

function plusSlides(n) {
  showSlides(slideIndex += n);
}

function currentDot(n) {
  showSlides(slideIndex = n);
}

function showSlides(n) {
    console.log('SHOWSLIDES');
      var i;
      var slides = document.getElementsByClassName("mySlides");
      var dots = document.getElementsByClassName("nav-dot");
      if (n > slides.length) {slideIndex = 1}
      if (n < 1) {slideIndex = slides.length}
      for (i = 0; i < slides.length; i++) {
          slides[i].style.display = "none";
      }
      for (i = 0; i < dots.length; i++) {
          dots[i].className = dots[i].className.replace(" active", "");
      }
      slides[slideIndex-1].style.display = "block";
      dots[slideIndex-1].className += " active";
}

or would it be better converting this to jquery and using .fadeOut() / .fadeIn()

If you want to do it with CSS, you can use a class or javascript to change `opacity` instead of `display`, and make sure you have the CSS `transition` property set for `opacity` (`transition: opacity 1s ease;`) — Alexander Nied, Oct 21 '16 at 13:27
I have gone through this peril before. Even with opacity teh bloc is still there. A pain and a challenge. Maybe have a look here: https://www.impressivewebs.com/animate-display-block-none/ — Daniel, Oct 21 '16 at 13:30

score 1 · Accepted Answer · edited May 23 '17 at 12:16

Before: Just look a little bit into it source of jQuery:

.fadeIn()

http://james.padolsey.com/jquery/#v=1.11.2&fn=fadeIn

.animation()

http://james.padolsey.com/jquery/#v=1.11.2&fn=animate

Here is an approach how you could possibly do it:

var fadeInBtn = document.getElementById('fadeIn');
fadeInBtn.addEventListener('click', function() {
  var testString = document.getElementById('test');
  fadeIn(testString, 30);
});

var fadeOutBtn = document.getElementById('fadeOut');
fadeOutBtn.addEventListener('click', function() {
  var testString = document.getElementById('test');
  fadeOut(testString, 60);
});



function fadeIn(element, speed) {
  var interval = setInterval(function () {
    
    var opacity = parseFloat(element.style.opacity);
    if(opacity >= 1.0) {
       clearInterval(interval);
    }

    element.style.opacity = opacity + 0.1;
  }, speed);
};

function fadeOut(element, speed) {
  var interval = setInterval(function () {
    
    var opacity = parseFloat(element.style.opacity);
    if(opacity <= 0) {
       clearInterval(interval);
    }

    element.style.opacity = opacity - 0.1;
  }, speed);
}

div {
  font-size: 300%;
}

<button id="fadeIn">Test .fadeIn()</button>
<button id="fadeOut">Test .fadeOut()</button>
<div id="test" style="opacity: 0">Example String</div>

Another solution is to use CSS(3) for this. I reference this already asked question here: Using CSS for fade-in effect on page load

creating fade out/in instead of display none/block

1 Answers1