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Changing the transform: scale attribute using JavaScript in a working function

So, basically, I am creating a slide show, and want to hide my div's until the fluted button in the top left gets clicked it shows. When I try to change the transform: scale() of my DIV (dots) it just doesn't change even after I try to run the function. I tried to just use a normal regex to convert its scale but for some reason, it still doesn't change even after I put the function in the onClick attribute. Could somebody help with why it isn't working even after I did step-by-step trials? Thank you!!
let slideIndex = 1;
//showSlides(slideIndex);
// Next/previous controls n = number selected in arrows
function plusSlides(n) {
showSlides(slideIndex += n);
}
// Thumbnail image controls
function currentSlide(nu) {
showSlides(slideIndex = nu);
}
function changeScale(newScale) {
var div1 = document.getElementById("dot1");
var div2 = document.getElementById("dot2");
var div3 = document.getElementById("dot3");
div1.style.transform = div1.style.transform.replace(/scale\([0-9|\.]*\)/, 'scale(' + newScale + ')');
div2.style.transform = div2.style.transform.replace(/scale\([0-9|\.]*\)/, 'scale(' + newScale + ')');
div3.style.transform = div3.style.transform.replace(/scale\([0-9|\.]*\)/, 'scale(' + newScale + ')');
}
function showSlides(n) {
//makes i variable, gets slides and dots on slideshow
let i;
let slides = document.getElementsByClassName("mySlides");
let dots = document.getElementsByClassName("dot");
//n = number inputted/selected
//dots.style.transform = dots.style.transform.replace(/scale\([0-9|\.]*\)/, 'scale(' + 1 + ')');
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";
}
.h2 {
font-family: 'Roboto', serif;
}
body {
background-color: #000;
}
.wrapper {
display: flex;
flex-direction: column;
width: 400px;
justify-content: center;
align-items: center;
border-radius: 3rem;
/*box-shadow: 0.6rem 0.6rem 1.9rem #525c5c, -0.5em -0.5em 1em #ffffff;
*/
z-index: 100;
transition-duration: 0.1s;
/* ADD */
}
.wrapper:hover {
text-shadow: 5px 5px 4px lightgray;
cursor: pointer;
transition-duration: 0.2s;
}
.wrapper .image {
overflow: hidden;
/* ADD */
border-radius: 1rem;
/* ADD */
}
.wrapper .image img {
width: 100%;
object-fit: cover;
border-radius: 1rem;
/*REMOVE */
cursor: pointer;
transition: transform 0.5s;
/* ADD */
}
.wrapper:hover img {
/* change scale? */
transform: scale(1.5);
}
.wrapper .infocontent {
display: flex;
justify-content: center;
align-items: center;
text-shadow: 0.5px 2px 10px rgba(214, 205, 205, 0.616);
font-weight: bold;
font-family: Consolas;
letter-spacing: 2px;
color: #441d9e;
cursor: pointer;
}
* {
box-sizing: border-box;
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}
/* Hide the images by default */
.mySlides {
display: none;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
margin-top: -22px;
padding: 16px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover {
background-color: rgba(53, 49, 49, 0.37);
}
.next:hover {
background-color: rgba(53, 49, 49, 0.37);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
#dot1 {
transform: scale(0);
}
#dot2 {
transform: scale(0);
}
#dot3 {
transform: scale(0);
}
.active,
.dot:hover {
background-color: #717171;
}
/* .hide{
}
*/
/* Fading animation */
.fade {
animation-name: fade;
animation-duration: 1.5s;
}
#keyframes fade {
from {
opacity: 0.4;
}
to {
opacity: 1;
}
}
<h1 class="h2">Flute</h1>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto">
<div class="wrapper">
<div class="image">
<img src="image1.webp" title="Golden Flute Background (possibly article?)" onclick="currentSlide(1); changeScale(4); ">
</div>
<div class="infocontent">
<h3><strong>Golden Flute</strong></h3>
</div>
</div>
<!-- Slideshow container -->
<div class="slideshow-container">
<!-- Full-width images with number and caption text -->
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img id="image" src="image1.webp" style="width:100%">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<!-- <img src="img2.jpg" style="width:100%">-->
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<!--<img src="img3.jpg" style="width:100%"> -->
<div class="text">Caption Three</div>
</div>
<!-- Next and previous buttons -->
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<!-- The dots/circles -->
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)" id="dot1"></span>
<span class="dot" onclick="currentSlide(2)" id="dot2"></span>
<span class="dot" onclick="currentSlide(3)" id="dot3"></span>
</div>

I think your problem is that div1.style.transform is an empty string in the beginning. Therefore the replace function doesn't find any matches to your regex that it could replace.
I don't see the necessity in using replace at all, you can just set the new value you want to have there. You could try it like this:
div1.style.transform = `scale(${newScale})`;
div2.style.transform = `scale(${newScale})`;
div3.style.transform = `scale(${newScale})`;

First image of slideshow does not load

I've just started with CSS and JavaScript, and I tried to make an image slider by looking into w3schools. The slider works, but the first image always comes empty only with the navigation bars being visible.but once I click the next button, it works fine.I'm not understanding what to change with this. Here's the code.
'use strict';
var slideIndex = 1;
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
//alert('showslides('+ n +')\nslideIndex='+slideIndex);
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("dot");
if (n === undefined) {
n = ++slideIndex;
}
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";
setTimeout(showSlides, 5000); // Change image every 5 seconds
}
* {
box-sizing: border-box;
}
body {
font-family: Verdana, sans-serif;
margin: 0
}
.mySlides {
display: none;
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<body>
<?php
include './p1.php';
// put your code here
?>
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img src="pics/bali2.jpg" height="400px" width="800px">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="pics/brazil1.jpg" height="400px" width="800px">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="pics/germany.jpg" height="400px" width="800px">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>
</body>

The slider works, but the first image always comes empty only with the navigation bars being visible
Just because of you apply css this mySlides on your, so your all div not visble. When you are click on next or previous or slider so particular container are showing.
So you need to apply the style="display: block;" on your first div.
DEMO
var slideIndex = 1,
interval;
function stopAndStart() {
if (interval) {
clearInterval(interval)
}
interval = setInterval(showSlides, 5000); // Change image every 5 seconds;
}
function plusSlides(n) {
showSlides(slideIndex += n);
stopAndStart()
}
function currentSlide(n) {
showSlides(slideIndex = n);
stopAndStart()
}
function showSlides(n) {
var i,
slides = document.getElementsByClassName("mySlides"),
dots = document.getElementsByClassName("dot");
if (n === undefined) {
n = ++slideIndex;
}
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";
}
stopAndStart();
body {
font-family: Verdana, sans-serif;
margin: 0
}
.mySlides {
display: none;
text-align: center;
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
background: burlywood;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<div class="slideshow-container">
<div class="mySlides fade" style="display: block;">
<div class="numbertext">1 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=1">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=2">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=3">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot active" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>

Restricting slideshow images to height/width of the slideshow container?

I have a modal image, that when clicked on open a slideshow, with a prev, and next button that are aligned halfway down from the top of the slideshow. When an image is longer than the slideshow container the slideshow becomes longer, rather than the image becoming smaller to fit the slideshow container (but stay centered).
I want it so that the container always stays the same size, and if the image is shorter, then I'd rather it be centered than moving up as it does now. (basically I want the next, and prev buttons to always in the same position, and halfway down the image). I've been stuck on this for a while, and
I've tried some stuff but none of it seems to work.
Note: the 1200x800 image is my standard for what I'd kind of like it to be like, the first pic is an example of too short, last is an example of too long.
Here is the [JSFIDDLE][1]
HTML:
<body>
<h2 style="text-align:center">Modal Albums</h2>
<div class="row">
<div class="column">
<img src="https://www.yosemitehikes.com/images/wallpaper/yosemitehikes.com-bridalveil-winter-1200x800.jpg" style="width:100%" onclick="openModal();currentSlide(1)" class="hover-shadow cursor">
</div>
</div>
<div id="myModal" class="modal">
<span class="close cursor" onclick="closeModal()">×</span>
<div class="modal-content">
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">2 / 4</div>
<img src="http://www.catholicevangelism.org/wp-content/uploads/2013/06/1200x800.gif" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">3 / 4</div>
<img src="http://www.a1carpet-to.com/wp-content/uploads/2015/08/600x400.png" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">4 / 4</div>
<img src="https://support.kickofflabs.com/wp-content/uploads/2016/06/800x1200.png" style="width:100%">
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
</div>
CSS:
body {
font-family: Verdana, sans-serif;
margin: 0;
}
* {
box-sizing: border-box;
}
.row > .column {
padding: 0 8px;
}
.row:after {
content: "";
display: table;
clear: both;
}
.column {
float: left;
width: 25%;
}
/* The Modal (background) */
.modal {
display: none;
position: fixed;
z-index: 1;
padding-top: 100px;
left: 0;
top: 0;
width: 100%;
height: 100%;
overflow: auto;
background: rgba(0, 0, 0, 0.9);
}
/* Modal Content */
.modal-content {
position: relative;
background-color: rgba(0, 0, 0, 0.9);
margin: auto;
padding: 0;
width: 90%;
max-width: 1200px;
}
/* The Close Button */
.close {
color: white;
position: absolute;
top: 10px;
right: 25px;
font-size: 35px;
font-weight: bold;
}
.close:hover,
.close:focus {
color: #999;
text-decoration: none;
cursor: pointer;
}
.mySlides {
display: none;
}
.cursor {
cursor: pointer
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -50px;
color: white;
font-weight: bold;
font-size: 20px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
-webkit-user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
text-decoration: none;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
img {
margin-bottom: -4px;
}
t img.hover-shadow {
transition: all .2s ease-in-out;
}
.hover-shadow:hover {
transform: scale(1.1);
}
.modal-content {
-webkit-animation-name: zoom;
-webkit-animation-duration: 0.6s;
animation-name: zoom;
animation-duration: 0.6s;
}
#-webkit-keyframes zoom {
from {
-webkit-transform: scale(0)
}
to {
-webkit-transform: scale(1)
}
}
#keyframes zoom {
from {
transform: scale(0)
}
to {
transform: scale(1)
}
}
JS:
function openModal() {
document.getElementById('myModal').style.display = "block";
}
function closeModal() {
document.getElementById('myModal').style.display = "none";
}
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("demo");
var captionText = document.getElementById("caption");
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";
captionText.innerHTML = dots[slideIndex - 1].alt;
}
EDIT:
![What i want it to look like]: https://imgur.com/a/jtmmM
the shaded in part is the actual image, the box I've drawn is the container (which ofc isn't actually visible on the page)

If you add the following CSS this should fix your issue.
I am not sure I understand exactly how you want things to scale.
After your comment I Found this post that may help you using object-fit
You will need to define a height for your container in this case I set it to 200px but you can pick whatever works best for you.
.mySlides {
text-align: center;
height: 200px;
}
.mySlides img {
width: 100%;
max-height:100%;
object-fit: contain;
}
jsfiddle
function openModal() {
document.getElementById('myModal').style.display = "block";
}
function closeModal() {
document.getElementById('myModal').style.display = "none";
}
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
// var dots = document.getElementsByClassName("demo");
var captionText = document.getElementById("caption");
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";
//captionText.innerHTML = dots[slideIndex - 1].alt;
}
body {
font-family: Verdana, sans-serif;
margin: 0;
}
* {
box-sizing: border-box;
}
.row>.column {
padding: 0 8px;
}
.row:after {
content: "";
display: table;
clear: both;
}
.column {
float: left;
width: 25%;
}
/* The Modal (background) */
.modal {
display: none;
position: fixed;
z-index: 1;
padding-top: 100px;
left: 0;
top: 0;
width: 100%;
height: 100%;
overflow: auto;
background: rgba(0, 0, 0, 0.9);
}
/* Modal Content */
.modal-content {
position: relative;
background-color: rgba(0, 0, 0, 0.9);
margin: auto;
padding: 0;
width: 90%;
max-width: 1200px;
}
/* The Close Button */
.close {
color: white;
position: absolute;
top: 10px;
right: 25px;
font-size: 35px;
font-weight: bold;
}
.close:hover,
.close:focus {
color: #999;
text-decoration: none;
cursor: pointer;
}
.mySlides {
display: none;
}
.cursor {
cursor: pointer
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -50px;
color: white;
font-weight: bold;
font-size: 20px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
-webkit-user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
text-decoration: none;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
img {
margin-bottom: -4px;
}
t img.hover-shadow {
transition: all .2s ease-in-out;
}
.hover-shadow:hover {
transform: scale(1.1);
}
.modal-content {
-webkit-animation-name: zoom;
-webkit-animation-duration: 0.6s;
animation-name: zoom;
animation-duration: 0.6s;
}
#-webkit-keyframes zoom {
from {
-webkit-transform: scale(0)
}
to {
-webkit-transform: scale(1)
}
}
#keyframes zoom {
from {
transform: scale(0)
}
to {
transform: scale(1)
}
}
.mySlides {
text-align: center;
height: 200px;
}
.mySlides img {
width: 100%;
max-height:100%;
object-fit: contain;
}
<h2 style="text-align:center">Modal Albums</h2>
<span ></span>
<div class="row">
<div class="column">
<img src="https://www.yosemitehikes.com/images/wallpaper/yosemitehikes.com-bridalveil-winter-1200x800.jpg" style="width:100%" onclick="openModal();currentSlide(1)" class="hover-shadow cursor">
</div>
</div>
<div id="myModal" class="modal ">
<span class="close cursor" onclick="closeModal()">×</span>
<div class="modal-content ">
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" >
</div>
<div class="mySlides">
<div class="numbertext">2 / 4</div>
<img src="http://www.catholicevangelism.org/wp-content/uploads/2013/06/1200x800.gif" >
</div>
<div class="mySlides">
<div class="numbertext">3 / 4</div>
<img src="http://www.a1carpet-to.com/wp-content/uploads/2015/08/600x400.png" >
</div>
<div class="mySlides">
<div class="numbertext">4 / 4</div>
<img src="https://support.kickofflabs.com/wp-content/uploads/2016/06/800x1200.png" >
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
</div>

Change your img style to ( style ="width:1900px;height:970px" align="middle" )
Example
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style ="width:1900px;height:970px" align="middle" >
</div>
And you need to do some changes in CSS too.

Change this in your HTML file ,
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style ="width:1900px;height:970px" align="middle" >
</div>

Javascript - CSS Slideshow not displaying default image

I am having an issue with CSS slideshow I've implemented into my current passion-project, in which there is no default image being displayed upon load of the web-page. Upon navigation/dot press, images are successfully displayed, but I can't seem to figure out the small code snippet (presumably missing from the Javascript function) that would display the first image on page load. I've attempted to simply add the "active" class to the desired image, but this only makes the 'dot' button appear active with no corresponding image being displayed. Appreciate any assistance
Here's the code:
var slideIndex = 1;
function plusSlides(n) {
'use strict';
showSlides(slideIndex += n);
}
function currentSlide(n) {
'use strict';
showSlides(slideIndex = n);
}
function showSlides(n) {
'use strict';
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("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";
}
* {
box-sizing: border-box
}
body {
font-family: Verdana, sans-serif;
margin: 0
}
.mySlides {
display: none
}
/* Slideshow container */
.slideshow-container {
max-width: 400px;
position: relative;
margin: auto;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add see-through background */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* */
.transition {
cursor: pointer;
height: 13px;
width: 13px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
/* */
.active,
.transition:hover {
background-color: #222;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
/* */
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* */
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<div class="homePage">
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 2</div>
<img src="graphics/logo.jpg" style="width:100%">
<div class="text"></div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 2</div>
<img src="graphics/1.jpg" style="width:100%">
<div class="text"></div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="transition" onclick="currentSlide(1)"></span>
<span class="transition" onclick="currentSlide(2)"></span>
<br>
</div>

You can give another class to the first image in the slider
<div class="mySlides fade block ">
<div class="numbertext">1 / 2</div>
<img src="#" style="width:100%">
<div class="text"></div>
</div>
Then you give it a display:block
.block {
display:block;
}
Example : https://jsfiddle.net/1ueun1L1/2/

Creating a Slideshow in different files

This is the html code
<!DOCTYPE html>
<html>
<head>
<title></title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" type="text/css" href="style2.css">
<script src="learn1.js"</script>
</head>
<body>
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img src="learnimg/1.jpg" style="width:100%">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="learnimg/2.jpg" style="width:100%">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="learnimg/3.jpg" style="width:100%">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">?</a>
<a class="next" onclick="plusSlides(1)">?</a>
</div>
<br>
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>
</body>
</html>`
This is the css code
* {box-sizing:border-box} body {font-family: Verdana,sans-serif;margin:0}
/* Slideshow container */ .slideshow-container { max-width: 1000px;
position: relative; margin: auto; }
/* Next & previous buttons */ .prev, .next { cursor: pointer;
position: absolute; top: 0; top: 50%; width: auto; padding:
16px; margin-top: -22px; color: white; font-weight: bold;
font-size: 18px; transition: 0.6s ease; border-radius: 0 3px 3px
0; }
/* Position the "next button" to the right */ .next { right: 0;
border-radius: 3px 0 0 3px; }
/* On hover, add a black background color with a little bit
see-through */ .prev:hover, .next:hover { background-color:
rgba(0,0,0,0.8); }
/* Caption text */ .text { color: #f2f2f2; font-size: 15px;
padding: 8px 12px; position: absolute; bottom: 8px; width: 100%;
text-align: center; }
/* Number text (1/3 etc) */ .numbertext { color: #f2f2f2;
font-size: 12px; padding: 8px 12px; position: absolute; top: 0;
}
/* The dots/bullets/indicators */ .dot { cursor:pointer; height:
13px; width: 13px; margin: 0 2px; background-color: #bbb;
border-radius: 50%; display: inline-block; transition:
background-color 0.6s ease; }
.active, .dot:hover { background-color: #717171; }
/* Fading animation */ .fade { -webkit-animation-name: fade;
-webkit-animation-duration: 1.5s; animation-name: fade; animation-duration: 1.5s; }
#-webkit-keyframes fade { from {opacity: .4} to {opacity: 1} }
#keyframes fade { from {opacity: .4} to {opacity: 1} }
/* On smaller screens, decrease text size */ #media only screen and
(max-width: 300px) { .slprev, .slnext,.text {font-size: 11px} }
This is the javascript code
var slideIndex = 1; showSlides(slideIndex);
function plusSlides(n) { showSlides(slideIndex += n); }
function currentSlide(n) { showSlides(slideIndex = n); }
function showSlides(n) { var i; var slides =
document.getElementsByClassName("mySlides"); var dots =
document.getElementsByClassName("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"; }
All these 3 codes are in different files. This is basically for the creation of a simple slideshow of three images. But when I execute this(all in different files) there is nothing to display(white screen in the browser). But when executed in a single html file(all contents in a single file) there is a perfect slideshow.
I cannot figure out this problem. Please help me out with this.

This doesn't seem right :
<script src="learn1.js"</script>
You forgot to close the opening tag, as such :
<script src="learn1.js"></script>
Plus, it's always a good habit to specify your resource type :
<script type="text/javascript" src="learn1.js"></script>

The code you posted seems to work just fine.
Maybe the image files isn't where you say they are?
Try opening the console and look for errors.
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("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";
}
{
box-sizing: border-box
}
body {
font-family: Verdana, sans-serif;
margin: 0
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 0;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 13px;
width: 13px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.slprev,
.slnext,
.text {
font-size: 11px
}
}
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img src="https://placeholdit.imgix.net/~text?txtsize=60&txt=1&w=100&h=100" style="width:100%">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="https://placeholdit.imgix.net/~text?txtsize=60&txt=2&w=100&h=100" style="width:100%">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="https://placeholdit.imgix.net/~text?txtsize=60&txt=3&w=100&h=100" style="width:100%">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>