random image; without repeating? - javascript

First off I'm not very familiar with javascript, thus here I am.
I have this code for my site to draw a random image. Working from this, how can I make the images not repeat? Thanks in adv! Code:
<script type="text/javascript">
var banner_list = ['http://i1233.photobucket.com/albums/ff389/lxluigixl/Cargo/LM_LogoMark4-4-2.gif', 'http://i1233.photobucket.com/albums/ff389/lxluigixl/Cargo/logobg_dome.png', 'http://i1233.photobucket.com/albums/ff389/lxluigixl/Cargo/logobg_brain.png']; $(document).ready(function() { var ran = Math.floor(Math.random()*banner_list.length);
$(".logobg img").attr(banner_list[ran]);
}); $(document).bind("projectLoadComplete", function(e, pid){
var ran = Math.floor(Math.random()*banner_list.length);
$(".logobg img").attr("src", banner_list[ran]);
}); </script>

After you display the image splice it out of the array, you can use banner_list.splice(ran, 1);. The arguments are .splice(index, howManyToRemove, howManyToInsert). Inserting is optional, so you can just use splice to start at the index of the image you're displaying and remove one. Make sure not to remove it until you're done referencing it.

You can use Array.splice() as Robert suggest with 2 Arrays. One for unsused and one for used images. Check my JSfiddle.
var images = ["http://www.fowkesauto.com/products_pictures/nutsbolt.jpg",
"http://i01.i.aliimg.com/photo/v0/114511763/Fasteners_Bolts_and_Nuts.jpg",
"http://us.123rf.com/400wm/400/400/DLeonis/DLeonis0810/DLeonis081000018/3706757-bolts-and-nuts-on-white.jpg",
"http://static3.depositphotos.com/1003288/173/i/950/depositphotos_1737203-Nuts-and-bolts.jpg"],
usedImages = [];
setInterval(function () {changeImage();},500);
var changeImage = function () {
var index = Math.floor(Math.random() * (images.length)),
thisImage = images[index];
usedImages.push(thisImage);
images.splice(index, 1);
if (images.length < 1) {
images = usedImages.splice(0, usedImages.length);
}
$("#image").attr("src", thisImage);
}

Related

How can we make Image Carousel with background Image Property

I'm making an image carousel i'm bounded to use background-image property instead of using
<img src="Image">
tag. my carousel is working if I use img tag . But its not working when I use background-image property, how can I modify my code with background-image property.
see my fiddle :https://jsfiddle.net/korLasen/ and update it please thanks :)
or you can see code here
(function(){
var image = $('#imageSlider');
var imageSet = ['http://www.exposureguide.com/images/top-ten-tips/top-ten-photography-tips-1e.jpg','http://images.clipartpanda.com/cliparts-images-aTqyrB8TM.png'];
var index = 0;
function imageSliderSet(){
image.setAttribute('data-background', imageSet[index]);
index++;
if(index >= imageSet.length){
index = 0;
}
}
setInterval = (imageSliderSet, 2000);
})();
This is quite a strange question... however, I am not one to judge :)
Here is a jsfiddle based on your example. I ended up using jquery for this. I hope this is somewhere near what you were looking for!
This is based on changing every two seconds. To extend that, you can change line 18 in the jquery. Here is the jquery:
$( document ).ready(function(){
var image = $('#imageSlider');
var imageSet = ['http://www.exposureguide.com/images/top-ten-tips/top-ten-photography-tips-1e.jpg','http://images.clipartpanda.com/cliparts-images-aTqyrB8TM.png'];
var index = 0;
window.setInterval(function(){
image.css('background-image', "url('" + imageSet[index] + "')");
index++;
if(index >= imageSet.length){
index = 0;
}
//here you can adjust the time interval for each photo
}, 2000);
});

How to make a picture change randomly in a website?

I want to make a website that the user will decide something. The user will click what he or she chose.
I want to know how to make the picture change to a random other picture everytime the user clicks it.
Is there any way to do that?
create an array with all the urls of the images you wanna use.
e.g.
HTML:
<img id='the-image-to-change'/>
JS:
var imageUrls = [
'http://placehold.it/255x255&text=A',
'http://placehold.it/255x255&text=B',
// ... more
'http://placehold.it/255x255&text=Z'
];
if you're not using jQuery:
var img = document.getElementById('the-image-to-change');
img.addEventListener("click", function() {
this.src = imageUrls[Math.floor(Math.random() * imageUrls.length)];
});
if jQuery (has not been tested)
img = $('#the-image-to-change');
img.on('click', function() {
this.src = imageUrls[Math.floor(Math.random() * imageUrls.length)];
});
This should give you the type of effect you want. Basically you're storing your images in an array, then you're going to randomly pick an index, then display it.
var yourImages = ["image1.png","image2.png","image3.png"];
var randomImage = Math.round(Math.random()*yourImages.length);
function displayImage()
{
document.write(yourImages[randomImage]);
}
Here is an example that's more geared toward what you asked, after I read your question again. If the user clicks on the image, it'll change to a random one.
JS:
<img id="currentImage" src="defaultImage.png" onclick="changePicture()">
<script>
function changePicture(){
var yourImages = ["image1.png","image2.png","image3.png"];
var randomImage = Math.round(Math.random()*yourImages.length);
var setImg = document.getElementById("currentImage").src;
setImg = yourImages[randomImage];
}
</script>
jQuery:
<img id="currentImage" src="defaultImage.png">
<script>
$("#currentImage").click(function(){
var yourImages = ["image1.png","image2.png","image3.png"];
var randomImage = Math.round(Math.random()*yourImages.length);
$("#currentImage").attr("src", yourImages[randomImage]);
});
</script>
Create an array of your picture, and use
Math.random();
To select a random index from your picture array that will be shown??

Changing multiple images source using jquery (and some other thing as well)

I am a beginner of javascript and jquery and i have 11 image tags in html. I want to
basically change sources of these tags using js and jquery. This code is not working and I am not getting any errors in firebug, can some one please tell me where I am doing wrong?
var imagesArray2=["01.png","02.png","03.png","04.png","05.png","06.png","07.png","08.png","09.png","10.png","11.png"];
var elementArray2 = ["#img1","#img2","#img3","#img4","#img5","#img6","#img7","#img8","#img9","#img10","#img11"];
var imagesArray,elementArray;
var elementInArray;
document ready
$(function(){
setInterval(Myfunction(),1000);});
my function code which has a loop based on elementsInArray variable value and it calls imageFadeAnimations function
function Myfunction(){
if(elementsInArray === 0){
imagesArray = imagesArray2;
elementArray = elementArray2;
elementsInArray = elementArray.length;
var imageChanges = Math.floor(Math.random()*elementsInArray);
imageFadeAnimations(imageChanges);
}
else
{
elementsInArray=elementArray.length;
imageChanges = Math.floor(Math.random()*elementsInArray);
imageFadeAnimations(imageChanges);
}
}
takes an integer as argument
function imageFadeAnimations(imageChanges){
for(var k = 0;k<imageChanges;k++){
var element = Math.floor(Math.random()*elementsinArray);
var image=Math.floor(Math.random()*elementsinArray);
imageChanger(elementArray[element],imageArray[image]);
elementArray.splice(element,1);
imagesArray.splice(image,1);
}
}
function imageChanger(b1,b2){
$(b1).fadeOut(500,function(){
$(b1).attr("src",b2);
$(b1).fadeIn(500);
});
}
You are making heavy weather out of something that jQuery can make very simple.
First wrap your images in an element (typically a div or a span) with id="imageContainer".
Now, if I understand correctly, your code will simplify to :
$(function() {
var imagesArray = ["01.png", "02.png", "03.png", "04.png", "05.png", "06.png", "07.png", "08.png", "09.png", "10.png", "11.png"],
$images = $("img", "#imageContainer");
setInterval(function() {
$images.each(function() {
var $img = $(this),
i = Math.min(imagesArray.length-1, Math.floor(Math.random() * imagesArray.length));
$img.fadeOut().promise().then(function() {
$img.attr("src", imagesArray[i]).fadeIn(500);
});
});
}, 1000);
});
EDIT 1
As #mplungjan points out below ...
If the img nodes were initialised with src attributes, then imagesArray can be composed by grabbing the srcs from the DOM as follows (replacing two lines above) :
var $images = $("img", "#imageContainer"),
imagesArray = $images.map(function() { return this.src; }).get();
I believe this jquery/zepto code is not the smaller, but the easier to understand:
function changeImg(){
$("#img1").attr('src', '01.png');
$("#img2").attr('src', '02.png');
$("#img3").attr('src', '03.png');
$("#img4").attr('src', '04.png');
$("#img5").attr('src', '05.png');
$("#img6").attr('src', '06.png');
};

Why is Javascript function not being called?

First Question on this site so I hope I do this right! I have a javascript function that I want to display an image (image1.jpg) when the page is loaded, and then every 2 seconds change the image by going through the loop. However only the first image is showing so it seems the JS function is not being called. Can anyone tell me if I am doing something wrong here because it looks fine to me so can't understand why it won't work. Thanks
<html>
<head>
<script type="text/javascript">
function displayImages(){
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
var i = 1;
if(i>images.length-1){
this.src=images[0];
i=1;
}else{
this.src=images[i];
i++;
}
setTimeout("displayImages()", 2000);
}
</script>
</head>
<body onload="displayImages();">
<img id="myButton" src="image1.jpg" />
</body>
</html>
You need to move the line
var i = 1;
outside the displayImages -function or it will start from one each time!
EDIT: But using a global variable is not considered good practice, so you could use closures instead. Also as noted in other answers, you are referencing this which does not refer to the image object, so I corrected that as well as simplified the logic a bit:
<script type="text/javascript">
function displayImages( i ){
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
var img = document.getElementById('myButton');
img.src = images[i];
i = (i+1) % images.length;
setTimeout( function() { displayImages(i); }, 2000 );
}
</script>
<body onload="displayImages(0);">
You need the value of i to be available at each call, it can be kept in a closure using something like:
var displayImages = (function() {
var i = 0;
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
return function() {
document.getElementById('myButton').src = images[i++ % images.length];
setTimeout(displayImages, 2000);
}
}());
Also, since this isn't set by the call, it will default to the global/window object, so you need to get a reference to the image. That too could be held in a closure.
There are a couple of issues here that are stopping this from working.
First the var i = 1; needs to be moved outside the function to make the increment work. Also note that the first item in an array is 0, not 1.
Second you're using this to refer to change the image's src, but this is not a reference to the image. The best thing to do is use here is document.getElementById instead.
var i, button;
i = 0;
button = document.getElementById('myButton');
function displayImages() {
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
if (i > images.length - 1){
button.src = images[0];
i = 0;
}
else{
button.src = images[i];
i++;
}
setTimeout(displayImages, 2000);
}
There's still some room for improvement and optimisation, but this should work.
You are reinitializing value of i every time, so change the following:
function displayImages(){
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
if(!displayImages.i || displayImages.i >= images.length) displayImages.i = 0;
document.getElementById('myButton').src = images[displayImages.i];
displayImages.i++;
setTimeout(displayImages, 2000);
}
Functions are objects in JS and because of this:
you can pass them by reference and not as a string improving performance and readability
you can add fields and even methods to a function object like I did with displayImages.i
EDIT: I've realized that there was one more issue src was not being set for button.
Now I've fixed this and also made other improvements.
Here is the fiddle http://jsfiddle.net/aD4Kj/3/ Only image URLs changed to actually show something.
<script type="text/javascript">
var i = 1;
function displayImages(){
.......
........
Just make "i" Global. so that whenever displayImages being called it will not redefined to 1.
<html>
<head>
<script type="text/javascript">
var i = 1;
function displayImages() {
var images = ['img1.jpg', 'img2.jpg', 'img3.jpg'];
i++;
if (i > images.length - 1) {
i = 0;
}
$('#myButton').attr('src', images[i]);
setTimeout(displayImages, 2000);
}
</script></head>
<body onload="displayImages();">
<img id="myButton" src="img1.jpg" height="150px" width="150px"/>
</body>
</html>
Make i global.
here your are using displayImages() recursively and variable for index i. e i assign as local variable in function displayImages() , you need to assign it global variable i.e outside of the function also initialize it from i=0 as array index always start from 0,
your code become
var i = 0; // assign i global
function displayImages(){
var images = ['image1.jpg', 'image2.jpg', 'image3.jpg'];
if(i>images.length-1){
document.getElementById('myButton').src=images[0]; //get img by id
i=0; // to get first image
}
else{
document.getElementById('myButton').src=images[i]; //get img by id
i++;
}
setTimeout("displayImages()", 2000);
}

showing random value in div element with javascript

I want my div element to work like a timer and shows random numbers with an interval of 1s. http://jsfiddle.net/NHAvS/46/. That is my code:
var arrData = [];
for (i=0;i<1000;i++)
{
arrData.push({"bandwidth":Math.floor(Math.random() * 100)});
}
var div = document.getElementById('wrapper').innerHTML =arrData;
document.getElementById('wrapper').style.left = '200px';
document.getElementById('wrapper').style.top = '100px';
but the problem is that it only shows 1 data at a time. any idea how to fix it?
Thanks
Do this:
setInterval(myfun,1000);
var div = document.getElementById('wrapper');
function myfun(){
div.innerHTML ='bandwidth :'+Math.floor(Math.random() * 100);
}
Take a Look: http://jsfiddle.net/techsin/NHAvS/49/
Note: your example was messed up as on left side it was set to load in head which means your div would be undefined every time your script loads before your dom. so setting it to onload make it works little more. :D
Note: also you seem to be chaining functions as in jquery, but in javascript you don't do that. The functions are made to do that. i.e. div= ..getElementById..innerHtml='balbla'; would set div = bla... not element.
You're better off using jQuery and CSS to achieve your desired result. jQuery to find the element and to display the random number; and CSS instead of manually setting the position. (Obviously jQuery is just a personal choice and document.getElementById will suffice - but if you're planning on manipulating the DOM a lot, jQuery is probably a better route to take). See updated fiddle
$(function () {
var arrData = [];
for (i = 0; i < 1000; i++) {
arrData.push({
"bandwidth": Math.floor(Math.random() * 100)
});
}
var index = 0;
setInterval(function(){
$("#wrapper").text(arrData[index].bandwidth);
index++;
}, 1000);
});
You can do it like this:
var delay = 1000, // 1000 ms = 1 sec
i;
setTimeout(function() {
document.getElementById('wrapper').innerHTML = arrData[i];
i++;
}, delay);

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