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hyperlinking an image in an array from another array

I have 2 arrays,I with images and another with links.
Using set interval I am changing the image in 2000millisec.
How can I hyperlink the image with the links.
var img_array = <?php echo json_encode($images); ?>;
var link_array = <?php echo json_encode($links); ?>;
var image = document.getElementById("aaa");
var index=0;
function slide(){
document["aaa"].src = img_array[index];
index++;
if(index>=img_array.length)
{
index=0;
}
}
setInterval("slide()",2000);
</script>

Here's an example. It's not perfect, because if you see it in the first time, the image is not loaded. This is why most of the sites generates all the images with links, and then just hide and show them.
var img_array = ["https://images.pexels.com/photos/853168/pexels-photo-853168.jpeg", "https://images.pexels.com/photos/46710/pexels-photo-46710.jpeg", "https://images.unsplash.com/photo-1529736576495-1ed4a29ca7e1"];
var link_array = ["index1.html","index2.html","index3.html"];
var image = document.getElementById("image");
var link = document.getElementById("link");
// The first (which is the 0) is already loaded, so we need to skip it from here.
var index = 1;
function slide(){
image.src = img_array[index];
link.href = link_array[index];
index++;
if(index >= img_array.length) {
index=0;
}
}
setInterval(slide, 2000);
<img src="https://images.pexels.com/photos/853168/pexels-photo-853168.jpeg" id="image" width="200">
Or if you can't change the DOM or you want to hide somewhy the url you can do something like this:
var img_array = ["https://images.pexels.com/photos/853168/pexels-photo-853168.jpeg", "https://images.pexels.com/photos/46710/pexels-photo-46710.jpeg", "https://images.unsplash.com/photo-1529736576495-1ed4a29ca7e1"];
var link_array = ["index1.html","index2.html","index3.html"];
var image = document.getElementById("image");
// The first (which is the 0) is already loaded, so we need to skip it from here.
var index = 1;
function slide(){
image.src = img_array[index];
index++;
if(index >= img_array.length) {
index=0;
}
}
image.addEventListener("click", function() {
// This is because of the sandbox environment.
console.log(link_array[index]);
// This is what you need.
window.open(link_array[index]);
});
setInterval(slide, 2000);
.pointer {
cursor: pointer;
}
<img src="https://images.pexels.com/photos/853168/pexels-photo-853168.jpeg" id="image" class="pointer" width="200">
However in this case maybe you will get blocked by the browser or if the click was registered after the new image was loaded, it may create a missclick.

How to change the text and its color using the value of a variable (i)

hi i'm trying to change the text and its color depending upon the value of the variable "i" and not using any eventlisteners! i'm getting cannot set property 'innerHTML' of null error is there any fix to this! thank you!
var i = 0;
var images= [];
var time = 3000;
var eventaction=0;
var timeoutId;
var dynamictext=document.querySelector("dynamictext");
images[0] = "https://i.pinimg.com/236x/f4/92/39/f492399e154bd9f564d7fc5299c19911--purple-rain-deep-purple.jpg";
images[1] = "https://image.shutterstock.com/image-photo/purple-butterfly-isolated-on-white-260nw-44004850.jpg";
images[2] = "https://www.birdscanada.org/images/inbu_norm_q_townsend.jpg";
function changeImg()
{if(i<images.length-1)
{i++;
}else
{i=0;}
document.getElementById('sliders').src=images[i];eventaction=0;
dynamictextchanger();
}
timeoutId=setTimeout("changeImg()", time);
}
function dynamictextchanger()
{
if(i==1)
{
dynamictext.innerHTML="Starter";
dynamicetxt.style.color="black";
}
else if(i==2)
{
dynamictext.innerHTML="veg";
dynamicetxt.style.color="green";
}
else if(i==3)
{
dynamictext.innerHTML="nonveg";
dynamicetxt.style.color="red";
}
}
window.onload=changeImg;
<p id="dynamictext"/>
<button class="button button3" id="leftbutton"> previous</button>
<img id="sliders" />
<button class="button button3" id="rightbutton">next</button>

You have forgotten the # sign on this line:
var dynamictext=document.querySelector("#dynamictext");

This code has way too many errors. I don't even know where to start. But some of these fixes should get you up and running.
Incorrect variable dynamicetxt.
Missing hash # symbol in querySelector method
Extra }
var i = 0;
var images= [];
var time = 3000;
var eventaction=0;
var timeoutId;
var dynamictext = document.querySelector("#dynamictext");
images[0] = "https://i.pinimg.com/236x/f4/92/39/f492399e154bd9f564d7fc5299c19911--purple-rain-deep-purple.jpg";
images[1] = "https://image.shutterstock.com/image-photo/purple-butterfly-isolated-on-white-260nw-44004850.jpg";
images[2] = "https://www.birdscanada.org/images/inbu_norm_q_townsend.jpg";
function changeImg()
{
if(i < images.length - 1) i++;
else i = 0;
document.getElementById('sliders').src=images[i];
eventaction=0;
dynamictextchanger(i);
timeoutId = setTimeout(changeImg, time);
}
function dynamictextchanger(i)
{
if(i==0)
{
dynamictext.innerHTML="Starter";
dynamictext.style.color="black";
}
else if(i==1)
{
dynamictext.innerHTML="veg";
dynamictext.style.color="green";
}
else if(i==2)
{
dynamictext.innerHTML="nonveg";
dynamictext.style.color="red";
}
}
window.onload = function(){ changeImg(); }
<p id="dynamictext"></p>
<button class="button button3" id="leftbutton"> previous</button>
<img id="sliders" />
<button class="button button3" id="rightbutton">next</button>

Javascript Next and Previous images

Code is supposed to show next image when clicking on next arrow and previous image when clicked on previous arrow. It does not work though. (error occurs while assigning img.src=imgs[this.i]; it says Cannot set property 'src' of null
at collection.next) .
Javascript code :
var arr = new collection(['cake.png', 'image2.png', 'image3.png', 'image1.png']);
function collection(imgs) {
this.imgs = imgs;
this.i = 0;
this.next = function(element) {
var img = document.getElementById('element')
this.i++;
if (this.i == imgs.length) {
this.i = 0;
}
img.src = imgs[this.i].src;
}
this.prev = function(element) {
var img = document.getElementById('element');
this.i--;
if (this.i < 0) {
this.i = imgs.length - 1;
}
img.src = imgs[this.i].src;
}
}
<!DOCTYPE html>
<html>
<head>
<title>photos</title>
<script src="photos.js"></script>
</head>
<body>
<input type='button' value='<' name='next' onclick="arr.next('mainImg')" />
<img id='mainImg' src="cake.png">
<input type='button' value='>' name='prev' onclick="arr.prev('mainImg')" />
</body>
</html>
Not using jquery. I do not have enough experience in js either. Thank you for your time

You had three mistakes:
You referenced the images as img.src = imgs[this.i].src; and you just had an array of strings, not an array of objects with a src property. img.src = imgs[this.i]; is the correct way to get the URL.
You used
var img = document.getElementById('element');
when you should have used
var img = document.getElementById(element);
element is an argument coming from your onclick event. It holds the id of your image that you should be using. "element" is just a string. You try to find an element with id equal to element which doesn't exist.
Edit: You should also use < and > to represent < and >. Otherwise your HTML might get screwed up. More on that here.
var arr = new collection(['http://images.math.cnrs.fr/IMG/png/section8-image.png', 'https://www.w3.org/MarkUp/Test/xhtml-print/20050519/tests/jpeg444.jpg', "http://saturnraw.jpl.nasa.gov/multimedia/images/raw/casJPGFullS72/N00183828.jpg"]);
function collection(imgs) {
this.imgs = imgs;
this.i = 0;
this.next = function(element) {
var img = document.getElementById(element);
this.i++;
if (this.i >= imgs.length) {
this.i = 0;
}
img.src = imgs[this.i];
};
this.prev = function(element) {
var img = document.getElementById(element);
this.i--;
if (this.i < 0) {
this.i = imgs.length - 1;
}
img.src = imgs[this.i];
};
this.next("mainImg"); // to initialize with some image
}
<!DOCTYPE html>
<html>
<head>
<title>photos</title>
<script src="photos.js"></script>
</head>
<body>
<input type='button' value='<' name='next' onclick="arr.next('mainImg')" />
<img id='mainImg' src="cake.png">
<input type='button' value='>' name='prev' onclick="arr.prev('mainImg')" />
</body>
</html>
This is how I'd personally do it:
var myCollection = new Collection([
"http://images.math.cnrs.fr/IMG/png/section8-image.png",
"https://www.w3.org/MarkUp/Test/xhtml-print/20050519/tests/jpeg444.jpg",
"http://saturnraw.jpl.nasa.gov/multimedia/images/raw/casJPGFullS72/N00183828.jpg"
], "mainImg");
document.getElementById("next_btn").onclick = function() {
myCollection.next();
};
document.getElementById("prev_btn").onclick = function() {
myCollection.prev();
}
function Collection(urls, imgID) {
var imgElem = document.getElementById(imgID);
var index = 0;
this.selectImage = function() {
imgElem.src = urls[index];
};
this.next = function() {
if (++index >= urls.length) {
index = 0;
}
this.selectImage();
};
this.prev = function(element) {
if (--index < 0) {
index = urls.length - 1;
}
this.selectImage();
};
// initialize
this.selectImage();
}
<!DOCTYPE html>
<html>
<head>
<title>photos</title>
<script src="photos.js"></script>
</head>
<body>
<input id="next_btn" type='button' value='<' />
<img id='mainImg'>
<input id="prev_btn" type='button' value='>' />
</body>
</html>

Why sending string into arr.next('mainImg') function ?
your img element always have the same id, only change src.
and document.getElementById(element) is also the same img element.
html: <img id='mainImg' src="cake.png">
js: document.getElementById('mainImg')
consider img element as a container, and id is it's identifiler.

var start_pos = 0;
var img_count = document.getElementsByClassName('icons').length - 1;
var changeImg = function(direction){
pos = start_pos = (direction == "next")? (start_pos == img_count)? 0 : start_pos+1 : (start_pos == 0)? img_count : start_pos-1;
console.log(pos)
}
document.getElementById('left').onclick = function(){ changeImg("previous"); }
document.getElementById('right').onclick = function(){ changeImg("next"); }

Why doesn't this mouseover/rollover work?

I have 3 images (pic1, pic2, pic3) that on click of the div ID change to (pic4, pic5, pic6). All this works fine but I need to put in a mouseover command that when hovering over pic2, it changes to pic 7 and on mouseout it goes back to pic 2. I am unsure as to why this part of my code isn't working, is it a syntax error? The two functions I am trying to use to do this are "rolloverImage" and "init".
HTML
<div id="content1">
<img src="pic1.jpg" alt="pic1"/>
<img src="pic2.jpg" alt="pic2" id="pic2"/>
<img src="pic3.jpg" alt="pic3"/>
</div>
Javascript
var g = {};
//Change background colors every 20 seconds
function changebackground() {
var backColors = ["#6AAFF7", "#3AFC98", "#FC9B3A", "#FF3030", "#DEDEDE"];
var indexChange = 0;
setInterval(function() {
var selectedcolor = backColors[indexChange];
document.body.style.background = selectedcolor;
indexChange = (indexChange + 1) % backColors.length;
}, 20000);
}
function rolloverImage(){
if (g.imgCtr == 0){
g.pic2.src = g.img[++g.imgCtr];
}
else {
g.pic2.src = g.img[--g.imgCtr];
}
}
function init(){
g.img = ["pic2.jpg", "pic7.jpg"];
g.imgCtr = 0;
g.pic2 = document.getElementById('pic2');
g.pic2.onmouseover = rolloverImage;
g.pic2.onmouseout = rolloverImage;
}
window.onload = function() {
var picSets = [
["pic1.jpg", "pic2.jpg", "pic3.jpg"],
["pic4.jpg", "pic5.jpg", "pic6.jpg"],
];
var currentSetIdx = 0;
var contentDiv = document.getElementById("content1");
var images = contentDiv.querySelectorAll("img");
refreshPics();
contentDiv.addEventListener("click", function() {
currentSetIdx = (currentSetIdx + 1) % picSets.length;
refreshPics();
});
function refreshPics() {
var currentSet = picSets[currentSetIdx];
var i;
for(i = 0; i < currentSet.length; i++) {
images[i].src = currentSet[i];
}
}
changebackground();
init();
}

How do I access and modify an image in an HTML page using javascript?

My HTML page has an image with id img. The idea is that by clicking first, previous, or next, the user can navigate through a set of images. How do I do this using JavaScript?

This should be a good start for you:
<script>
var imgs = ["img1.png","img2.png","img3.png"]; // copy images to the same dir
var index = 0;
</script>
<img src="img1.png" onclick="this.src=imgs[++index%imgs.length]"/>
click the image to slide.
If you need buttons, see this example:
<img id="clicker" src="img1.png"/>
Prev
Next
First
Last
<script>
var imgs = ["img1.png","img2.png","img3.png"];
var index = 0;
var clicker = document.getElementById("clicker");
function prev() { clicker.src = imgs[--index%imgs.length]; }
function next() { clicker.src = imgs[++index%imgs.length]; }
function first() { clicker.src = imgs[index=0]; }
function last() { clicker.src = imgs[index=imgs.length-1]; }
</script>
The return false means that default action on click (follow the link) is supressed. Javascript can access elements i.e. using id (see clicker here). Once you get comfortable with this and you start to solve browser compatibility problems, it is good idea to continue with jQuery (as the other suggests), MooTools or other framework.

Use jQuery!
var myImg = $("#myimg");
$("#next").click(function(){
var id = myImg.attr("data-id") + 1;
myImg.attr("src", "image"+id+".jpg");
});
$("#prev").click(function(){
var id = myImg.attr("data-id") -1;
myImg.attr("src", "image"+id+".jpg");
});
HTML:
<img id="myimg" src="image1.jpg" data-id="1">
Next<br>
Previous<br>
This is a very dummy example. There are numerous slideshow plugins out there!

No need jQuery:
<script type='text/javascript'>
window.onload = function() {
var imageSrcs= ['1.jpeg', '2.jpg', '3.jpg'];
var index = 0;
var image = document.getElementById('img');
var previous = document.getElementById('previous');
previous.onclick = function() {
index -= 1;
if(index < 0) index = imageSrcs.length - 1;
image.src = imageSrcs[index];
}
var next = document.getElementById('next');
next.onclick = function() {
index += 1;
if(index == imageSrcs.length) index = 0;
image.src = imageSrcs[index];
}
}
</script>
And html:
<img src='1.jpeg' id='img'>
<div>
<span id='previous'>Previous</span>
<span id='next'>Next</span>
</div>

You do not need a library for this. Something like this will change the image url, where "theImg" is the id of the image:
document.getElementById("theImg").src = "newUrl.png";
To do it without explicit ids, this will change the url where i is the index of the image:
document.getElementsByTagName("img")[i].src = "newUrl.png";

Try something like this (untested):
LOAD JQUERY:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" type="text/javascript"></script>
JAVASCRIPT:
<script type='text/javascript'>
var lst_src = ['img1.jpg', 'img2.png', 'img3.gif'];
$('a', '#nav').click(function(e) {
e.preventDefault();
var src_current = $('#img').attr('src');
var index = lst_src.indexOf(src_current);
var len = lst_src.length;
var action = $(this).attr('class');
switch ($action) {
case 'previous' : var i = index - 1;
if (i < 0) src_current = lst_src[len + i];
else src_current = lst_src[i];
break;
case 'next' : var i = index + 1;
if (i > len) src_current = lst_src[i - len];
else src_current = lst_src[i];
break;
case 'first' : src_current = lst_src[0];
break;
case 'last' : src_current = lst_src[len - 1];
break;
}
$('#img').attr('src', src_current);
});
</script>
HTML: Use the class of a link to denote the required action:
<img id='img' src='img1.jpg'>
<p id='nav'>
<a href='' class='first'>←←First</a>
<a href='' class='previous'>←Previous</a>
<a href='' class='next'>Next→</a>
<a href='' class='last'>Last→$rarr;</a>
</p>