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how hide the div when click on the another div

when I click another div it is coming down the previous div but I want it should come at the same place of the previous div without clicking the previous div(to close)
<div class="col-sm-6 col-lg-3 " onclick="drop_down('drop1')"> (CARD) </div>
<div class="col-sm-6 col-lg-3 " onclick="drop_down('drop2')"> (CARD) </div>
<div class="drop col-12" id="drop1" style="display:none" >..</div>
<div class="drop col-12" id="drop2" style="display:none" >..</div>
function drop_down(e){
var x = document.getElementById(e);
if(x.style.display === "none"){
x.style.display = "block";
}
else{
x.style.display = "none";
}
}

If I understand your problem statement, you want the visible drop down to hide before the new drop down is shown.
To do that, simply hide all the dropdowns before performing your logic:
function drop_down(e){
var x = document.getElementById(e);
const xIsShowing = x.style.display === "block";
document.getElementById('drop1').style.display = 'none';
document.getElementById('drop2').style.display = 'none';
if(!xIsShowing) {
x.style.display = "block";
}
}

Something like this?
function drop_down(e){
var drop = document.getElementsByClassName('drop')
for(var i = 0; i < drop.length; i++){
if(e == drop[i].id){
drop[i].style.display = "block";
}
else{
drop[i].style.display = "none";
}
}
}
<div class="col-sm-6 col-lg-3" onclick="drop_down('drop1')"> (CARD) </div>
<div class="col-sm-6 col-lg-3" onclick="drop_down('drop2')"> (CARD) </div>
<div class="drop col-12" id="drop1" style="display:none" >Div one</div>
<div class="drop col-12" id="drop2" style="display:none" >Div two</div>

How to toggle/switch the classes between three or more divs in a sequence?

How can I easily toggle/switch the classes between three or more divs in a sequence by click?
Example html:
<div class="box">Box 1</div>
<div class="box active">Box 2</div>
<div class="box">Box 3</div>
<div class="next">Next</div>
<div class="back">Back</div>
This way just works with two:
$(".next, .back").click(function(){
$(".box").toggleClass("active");
});

Simply to check if nth-child has the active class and loop.
$(".next").click(function(){
$(".box").each( function(i, j) {
if( $(this).hasClass('active') ) {
$(this).removeClass('active');
$(".box:nth-child("+(((i+1)%$(".box").length)+1)+")").addClass('active');
return false;
}
});
});
$(".back").click(function(){
$(".box").each( function(i, j) {
if( $(this).hasClass('active') ) {
$(this).removeClass('active');
$(".box:nth-child("+(((i-1)+$(".box").length)%$(".box").length+1)+")").addClass('active');
return false;
}
});
});
.active {
background-color: red;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div>
<div class="box">Box 1</div>
<div class="box active">Box 2</div>
<div class="box">Box 3</div>
<div class="back">Back</div>
<div class="next">Next</div>
</div>

This is pretty generic
$(".nav").on("click", function() {
var dir = $(this).is(".next") ? 1 : -1; // which direction are we going?
var active = $(".box.active").index() - 1;
var $boxes = $(".box");
active += (1 * dir);
if (active < 0) active = $boxes.length - 1; // wrap
else if (active >= $boxes.length) active = 0;
$(".box").removeClass("active");
$(".box").eq(active).addClass("active");
});
.active {
color: red
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="box">Box 1</div>
<div class="box active">Box 2</div>
<div class="box">Box 3</div>
<br/>
<div class="nav back">Back</div>
<div class="nav next">Next</div>

I've created another solution that gets the button's ID (which I've added) and uses that to dictate where to go.
var box = $('.box');
var maxBoxes = box.length;
$("#nextBtn, #backBtn").click(function() {
var getBtn = $(this).get(0).id,
activeBox = $('.box.active'),
position = activeBox.index();
activeBox.removeClass('active');
if (getBtn === 'nextBtn') {
(position == maxBoxes) ? box.eq(0).addClass('active'): activeBox.next().addClass('active');
} else {
(position === 1) ? box.last().addClass('active'): activeBox.prev().addClass('active');
}
});
.active {
color: red;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="box">Box 1</div>
<div class="box">Box 2</div>
<div class="box active">Box 3</div>
<div id="nextBtn" class="next">Next</div>
<div id="backBtn" class="back">Back</div>

I think that the following should be efficient, because it will not do unnecessary checks.
var last = $(".active")
function toggle(dir){
var future = last[dir]();
if(!(future.length && future.hasClass('box'))) {
return;
}
last.toggleClass("active")
last = future
last.toggleClass("active");
}
$(".next").click(toggle.bind(void 0, 'next'));
$(".back").click(toggle.bind(void 0, 'prev'));

Double onclick events not working

I have a tab menu on my website and the code used for it works perfectly. JavaScript:
function openTab(tabName) {
var i;
var x = document.getElementsByClassName("tab");
for (i = 0; i < x.length; i++) {
x[i].style.display = "none";
}
document.getElementById(tabName).style.display = "flex";
}
HTML:
<div class="col-md-4">
<div onclick="openTab('tab-1')" class="tab-button">
<h5>IT Problems</h5>
</div>
</div>
<div class="col-md-4">
<div onclick="openTab('tab-2')" class="tab-button">
<h5>Save Time</h5>
</div>
</div>
<div class="col-md-4">
<div onclick="openTab('tab-3')" class="tab-button">
<h5>Cost Effective</h5>
</div>
</div>
And then obviously I applied the IDs ("tab-[1/2/3]") and classes ("tab") to the divs I want as tabs. However, when I replicate the exact same code to have a tab button highlighted for the current tab open, it doesn't work. JavaScript:
function selectedTab(selectName) {
var i;
var x = document.getElementsByClassName("select");
for (i = 0; i < x.length; i++) {
x[i].style.border-bottom-color = "#dbdbdb";
}
document.getElementById(selectName).style.border-bottom-color = "#25a7df";
}
HTML:
<div class="col-md-4">
<div onclick="openTab('tab-1'); selectedTab('select-1')" class="tab-button">
<h5 id="select-1" class="select">IT Problems</h5>
</div>
</div>
<div class="col-md-4">
<div onclick="openTab('tab-2'); selectedTab('select-2')" class="tab-button">
<h5 id="select-2" class="select">Save Time</h5>
</div>
</div>
<div class="col-md-4">
<div onclick="openTab('tab-3'); selectedTab('select-3')" class="tab-button">
<h5 id="select-3" class="select">Cost Effective</h5>
</div>
</div>
I've looked literally everywhere online and had multiple people look at this and nobody can find a solution. Can anyone help?

border-bottom-color is not a valid style property, you need to replace hyphen case with camel case
You need to use the borderBottomColor property of style in selectTab method
function selectedTab(selectName) {
var x = document.getElementsByClassName("select");
for (var i = 0; i < x.length; i++) {
x[i].style.borderBottomColor = "#dbdbdb"; //observe style property Change
}
document.getElementById(selectName).style.borderBottomColor = "#25a7df";
}

Showing and hiding div tags by their ID order using a button

I made a small questionnaire and I placed each question in a div tag. I'm trying to display the div tags in order, so when the user click the "Next" button it will move on to the next div and hide the previous one. Kind of like a paging system? I thought about creating some sort of a for loop but I feel like my code is super messy. Any suggestions? Thanks in advance.
<form>
<div id="1"></div>
<div id="2"></div>
<div id="3"></div>
<div id="4"></div>
<div id="5"></div>
<div id="6"></div>
<div id="7"></div>
<div id="8"></div>
<div id="9"></div>
<div id="10"></div>
<button type="button">Next</button>
<button type="button">Back</button>
</form>
<script>
visible(){
document.getElementById('1').style.display = "block";
document.getElementById('2').style.display = "none";
document.getElementById('3').style.display = "none";
document.getElementById('4').style.display = "none";
document.getElementById('5').style.display = "none";
document.getElementById('6').style.display = "none";
document.getElementById('7').style.display = "none";
document.getElementById('8').style.display = "none";
document.getElementById('9').style.display = "none";
document.getElementById('10').style.display = "none";
}

You can use javascript functions to setup your divs. This uses jQuery for smooth transition as well.
<div id="1">Question 1</div>
<div id="2" class="hidden">Question 2</div>
<div id="3" class="hidden">Question 3</div>
<div id="4" class="hidden">Question 4</div>
<div id="5" class="hidden">Question 5</div>
<div id="6" class="hidden">Question 6</div>
<div id="7" class="hidden">Question 7</div>
<div id="8" class="hidden">Question 8</div>
<div id="9" class="hidden">Question 9</div>
<div id="10" class="hidden">Question 10</div>
<button type="button" onclick="reverseDiv();">Back</button>
<button type="button" onclick="advanceDiv();">Next</button>
<script>
var divNum=1;
advanceDiv = function() {
if(divNum < 10) {
divNum++;
$('#' + (divNum-1)).slideToggle();
$('#' + divNum).slideToggle();
}
else {
/* last slide reached */
alert('last question');
}
}
reverseDiv = function() {
if(divNum > 1) {
divNum--;
$('#' + (divNum+1)).slideToggle();
$('#' + divNum).slideToggle();
}
else {
alert('first question');
}
}
</script>
Here's a jsfiddle to show functionality (and also includes arrow keys to move between functions): https://jsfiddle.net/79xupebb/1/

To think about the start and the end in this is case is important.
What happens if you are at the end and then click the next button? Then you have to go to the start. And if you are at the start point and click the previous button, you have to go to the end:
if(current === start && direction === "prev") current = end;
if(current === end && direction === "next") current = start;
To make all the divs display: none and only the first one display: block use CSS, like:
#container div {
display: none;
}
#container div:first-child {
display: block;
}
with HTML
<div id="container">
<div id="1">div1</div>
<div id="2">div2</div>
<div id="3">div3</div>
...
</div>
All togehter with plain JavaScript:
var prev = document.getElementById("prev");
var next = document.getElementById("next");
var start = 1;
var end = 10;
var current = 1;
function slide(direction, start, end) {
document.getElementById(current).style.display = "none";
if(current === start && direction === "prev") {
current = end;
} else if(current === end && direction === "next") {
current = start;
} else if(direction === "next") {
current += 1;
} else if(direction === "prev") {
current -= 1;
}
document.getElementById(current).style.display = "block";
}
prev.addEventListener("click", function() {
slide("prev", start, end);
});
next.addEventListener("click", function() {
slide("next", start, end);
});
#container div {
display: none;
}
#container div:first-child {
display: block;
}
<div id="container">
<div id="1">div1</div>
<div id="2">div2</div>
<div id="3">div3</div>
<div id="4">div4</div>
<div id="5">div5</div>
<div id="6">div6</div>
<div id="7">div7</div>
<div id="8">div8</div>
<div id="9">div9</div>
<div id="10">div10</div>
<button id="prev" type="button">Previous</button>
<button id="next" type="button">Next</button>
</div>

There is a simple way to do what you want. Use a counter (current), start it at 1 and increase it/ decrease it whenever the user clicks one of the buttons, then loop through your div list and make them all display:none except the one that corresponds to your current value.
var current = 1;
function next(){
current+=1;
for(var i = 1; i<10; i++){
document.getElementById(i).style.display = ((current==i)?"block":"none");
}
}
function back(){
current-=1;
for(var i = 1; i<=10; i++){
document.getElementById(i).style.display = ((current==i)?"block":"none");
}
}
<form>
<div id="1" style="display:block">one</div>
<div id="2" style="display:none">two</div>
<div id="3" style="display:none">three</div>
<div id="4" style="display:none">four</div>
<div id="5" style="display:none">five</div>
<div id="6" style="display:none">six</div>
<div id="7" style="display:none">aaaa</div>
<div id="8" style="display:none">bbb</div>
<div id="9" style="display:none">nnn</div>
<div id="10" style="display:none">ggg</div>
<button type="button" onclick="next()">Next</button>
<button type="button" onclick="back()">Back</button>
</form>
Note: My code has no safeguards so it will go below 1 and above 10, you can always check with an if statement in each of the buttons' functions.

var i;
for(i=2;i<=10;i++)
document.getElementById(''+i).style.display = "none";
i=1;
document.getElementById('btnNext').onclick = function(){
document.getElementById(''+i).style.display = "none";
i++;
document.getElementById(''+i).style.display = "block";
}
document.getElementById('btnPrev').onclick = function(){
document.getElementById(''+i).style.display = "none";
i--;
document.getElementById(''+i).style.display = "block";
}
<form>
<div id="1">1</div>
<div id="2">2</div>
<div id="3">3</div>
<div id="4">4</div>
<div id="5">5</div>
<div id="6">6</div>
<div id="7">7</div>
<div id="8">8</div>
<div id="9">9</div>
<div id="10">10</div>
<button type="button" id="btnNext">Next</button>
<button type="button" id="btnPrev">Back</button>
</form>

Add the onclick property to your buttons first:
<button type="button" onclick="showNext()">Next</button>
<button type="button" onclick="showPrev()">Back</button>
Then retrieve the divs by adding the class="quest" to every div
var el = document.getElementsByClassName("quest");
function showNext(){
for(var i=0;i<el.length; i++){
if (el[i].style.display == "block"){
el[i].style.display = "none";
if ((i+1)==el.length) i=-1;
el[i+1].style.display = "block";
break;
}
}
}
function showPrev(){
for(var i=0;i<el.length; i++){
if (el[i].style.display == "block"){
el[i].style.display = "none";
if (i==0) i=el.length;
el[i-1].style.display = "block";
break;
}
}
}

JQuery run a function when a div shows

I want to run a function when a div shows.
HTML:
<div id="holder">
<div id="main1" class="container-fluid">
<h1>Header 1</h1>
<div class="btn btn-default pull-right" onclick="show('main2');">Next</div>
</div>
<div id="main2" class="container-fluid" style="display:none;">
<h1>Header 2</h1>
<div class="btn btn-default pull-right" onclick="show('main3');">Next</div>
</div>
<div id="main3" class="container-fluid" style="display:none;">
<h1>Header 3</h1>
</div>
</div>
JS:
function show(elementID) {
var ele = document.getElementById(elementID);
if (!ele) {
alert("no such element");
return;
}
var pages = document.getElementsByClassName('container-fluid');
for (var i = 0; i < pages.length; i++) {
pages[i].style.display = 'none';
}
ele.style.display = 'block';
}
I want to run a function when my #main3 shows. The function is to set a timer so that after showing #main3 for 10 sec, it will show #main1.
Now how do I detect when my #main3 shows?

You can check for elementID, if it is main3, then set setTimeout for 10000 ms (10s) and call show('main1') in timeout after the line ele.style.display = 'block'; as following:
function show(elementID) {
var ele = document.getElementById(elementID);
if (!ele) {
alert("no such element");
return;
}
var pages = document.getElementsByClassName('container-fluid');
for(var i = 0; i < pages.length; i++) {
pages[i].style.display = 'none';
}
ele.style.display = 'block';
if(elementID == "main3"){
setTimeout(function(){ show("main1"); }, 10000);
}
}
DEMO

Since you have used jQuery tag, you can use a jQuery solution in which we can see whether the current tab is the last one if so then use a timer to show the first one like
jQuery(function($) {
$('#holder .nxt').click(function() {
var $parent = $(this).parent();
var $next = $parent.hide().next().show();
if ($next.is(':last-child')) {
setTimeout(function() {
$next.hide().siblings().first().show();
}, 2500)
}
})
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="holder">
<div id="main1" class="container-fluid">
<h1>Header 1</h1>
<div class="btn btn-default pull-right nxt">Next</div>
</div>
<div id="main2" class="container-fluid" style="display:none;">
<h1>Header 2</h1>
<div class="btn btn-default pull-right nxt">Next</div>
</div>
<div id="main3" class="container-fluid" style="display:none;">
<h1>Header 3</h1>
</div>
</div>

after this:
ele.style.display = 'block';
you can have a check like:
ele.style.display = 'block';
if(ele.id === "main3"){
// call it here.
}

function show(elementID) {
var ele = document.getElementById(elementID);
if (!ele) {
alert("no such element");
return;
}
var pages = document.getElementsByClassName('container-fluid');
for(var i = 0; i < pages.length; i++) {
pages[i].style.display = 'none';
}
ele.style.display = 'block';
if(elementID=='main3'){
yourFunction();// call your function here!
}
}