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Perform operations on button values in JavaScript

I'm trying to make a calculator in JS and I'm searching for ways to add, subtract, multiply and divide button values. I've created a function to display the buttons but now I realize that that might not be necessary and I might need just one function which displays and does the operation.
HTML code:
<div class="numbers">
<button value="1" onclick="displayButtons(this)">1</button>
<button value="2" onclick="displayButtons(this)">2</button>
<button value="3" onclick="displayButtons(this)">3</button>
<button value="4" onclick="displayButtons(this)">4</button>
<button value="=" id="calculate" onclick="performOperations(this)">=</button>
**etc.**
<div class="operations">
<button value="+" onclick="displayButtons(this)" style="width: 2rem; top: 5rem;">+</button>
<button value="-" onclick="displayButtons(this)" style="left: -6rem; top: 5rem;">-</button>
**etc.**
JS code:
function displayButtons(button) {
outputDiv.innerHTML += button.value
}
function performOperations(button) {
var val = parseFloat(button.getAttribute("value"));
var total = parseFloat(document.getElementById('output').getAttribute("value"));
document.getElementById('output').innerHTML = total + val;
}
That is my attempt to do addition the button values and I have the performOperations called on the "=" sign which currently displays NaN onclick. (I'm working on the addition first).
Any push in the right direction is appreciated. Thank you!

You're right that you can use one function to do all the work but it means that you have to mark up your HTML with classes and data-attributes.
In this example I've used CSS grid to display the various calculator buttons. The "equals" and "clear" buttons have a data attribute to help the function decide what operation to do.
// Cache our elements and add an event listener
// to the button container. `handleClick` returns a
// new function that is called when the listener is fired
const output = document.querySelector('.output');
const buttons = document.querySelector('.buttons');
buttons.addEventListener('click', handleClick(), false);
function handleClick() {
// Initialise the sum
const sum = [];
// Return the function that will be called
// when a click event occurs
return function(e) {
// Because we're using event delegation (details
// below) we need to check that the element that
// was clicked was a button
if (e.target.matches('.button')) {
// Destructure the type from the dataset, and
// the text content
const { dataset: { type }, textContent } = e.target;
// `switch` on the type
switch (type) {
// If it's equals evaluate the elements in
// the array, and output it
case 'equals': {
output.textContent = eval(sum.join(''));
break;
}
// Clear empties the array, and clears
// the output
case 'clear': {
sum.length = 0;
output.textContent = '';
break;
}
// Otherwise add the textContent to
// the array, and update the output
default: {
sum.push(textContent);
output.textContent = sum.join(' ');
break;
}
}
}
}
}
.container{width:175px;}
.buttons {display: grid; grid-template-columns: repeat(4, 40px);grid-gap:0.3em;}
.button {display:flex;justify-content:center;align-items:center;background-color: #efefef; border: 1px solid #565656;padding: 0.5em;}
.button:not(.void):hover {background-color: #dfdfdf; cursor:pointer;}
.output {height: 20px; padding: 0.5em 0.2em;font-size: 1.2em;border:1px solid #565656;margin-bottom: 0.2em;}
<div class="container">
<div class="output"></div>
<div class="buttons">
<div class="button">7</div>
<div class="button">8</div>
<div class="button">9</div>
<div class="button">*</div>
<div class="button">4</div>
<div class="button">5</div>
<div class="button">6</div>
<div class="button">/</div>
<div class="button">1</div>
<div class="button">2</div>
<div class="button">3</div>
<div class="button">-</div>
<div class="button">0</div>
<div data-type="clear" class="button">C</div>
<div data-type="equals" class="button">=</div>
<div class="button">+</div>
</div>
</div>
Additional documentation
Destructuring assignment
Event delegation

Move button when clicked

How do I move the button from the div with id of two to the div with id of one when I click the button?
<div id="one">
</div>
<div id="two">
<button onclick="moveMe"></button>
</div>
function moveMe() {
// ??
}

We can do this using removeChild and appendChild js features. Provided an example below with working code.
const one = document.getElementById("one");
const two = document.getElementById("two");
const allButtons = document.getElementsByTagName("button");
for(let i = 0; i < allButtons.length; i++) {
const btn = allButtons[i];
btn.addEventListener("click", function(e) {
const el = e.currentTarget;
const newParent = el.parentNode.id == "one" ? two : one;
el.parentNode.removeChild(el);
newParent.appendChild(el)
});
}
.section {
height: 100px;
width: 150px;
padding: 4px;
margin: 5px;
float: left;
}
#one {
background: #CCC;
}
#two {
background: #eee;
}
button {
margin: 2px;
padding: 4px;
}
<h3>Toggle button between container on click</h3>
<div>
<div class="section" id="one"></div>
<div class="section" id="two"> <button>Move me 1</button> <button>Move me 2</button></div>
</div>

function moveMe() {
const divTwo = document.getElementById("two")
const divOne = document.getElementById("one")
const newButton = document.createElement("button")
newButton.innerText = "Click me"
divOne.appendChild(newButton)
divTwo.children[1].remove()
}
<div id="one">
<p>
div one
</p>
</div>
<div id="two">
<p>
div two
</p>
<button onclick="moveMe()">Click me</button>
</div>

You can try this:
// select the elements
const button = document.querySelector('button');
const firstDiv = document.getElementById('one');
// add eventListener
button.addEventListener('click', moveButton);
// move the button
function moveButton() {
firstDiv.append(button);
}

<div id="one">
</div>
<div id="two">
<button id="btn" onclick="moveMe">MoveMe</button>
</div>
function moveMe() {
var divOne = document.querySelector("#one");
var btn = document.querySelector("#btn");
divOne.appendChild(btn);
}

You can use code below to move the element.
There's some changes that I made on your code,
you can use version 1 or version 2
the changes on first version is i add "id" attribute on the element so we don't resort to use the tag only as selector, of course you can also use #two>button to make it more precise
the changes on second version is i add a parameter to your function this time it will handle the current element using "this" keyword when calling the function
function moveMe(){
// one.appendChild(document.querySelector("button"));
one.appendChild(move);
}
function moveMeV2(element){
one.appendChild(element);
}
<div id="one">
<span>one</span>
</div>
<div id="two">
<span>two</span>
<button id="move" onclick="moveMe()">Move Me</button>
<button onclick="moveMeV2(this)">Move Me V2</button>
</div>

Show and Hide the text with stars on clicking the button

I have a paragraph tag with number init. I want to replace the numbers with stars/round circles on clicking the button beside it. Also, I am attaching a screenshot to which I want to apply the concept(on clicking the eye icon the Patient Id should be replaced with round circles and vice versa). Attaching the code which I have tried. Your solutions are very important for me in learning the things. TIA
enter image description here
$('.hide-id').on('click', function () {
$('.patient-id-content').attr('type', 'password');
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="container">
<p>
<span class="patient-id-content" type="text">34324345</span>
<button class="hide-id">
Hide
</button>
</p>
</div>

Here is what you need.
$(".hide-id").on("click", function () {
var span = $(".patient-id-content");
var spanText = span.text();
if (!spanText.indexOf("*")) {
$(".patient-id-content").text(span.attr("data-oldText"));
return;
}
var starText = "";
for (let i = 0; i < spanText.length; i++) starText += "*";
$(".patient-id-content")
.attr("data-oldText", spanText)
.text(starText);
});
working example on jsfiddle: https://jsfiddle.net/ynojkf0q/

So your jQuery code from the OP was not correct. You have what you want as the password in a span and are applying a type attribute to that.
If you check the MDN Docs, you will learn that there is no type attribute for a span, as spans only support Global Attributes. The input element uses both the type: text and type: password, see the docs here.
But if you want to have the span as your element, you can change your jQuery event handler to the following: .toggleClass('hidden'); and create a hidden CSS class with the properties display: none;
$('.hide-id').on('click', function () {
$('.patient-id-content').toggleClass('hidden');
});
.hidden { display: none;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="container">
<p>
<input class="patient-id-content" type="text" value="34324345">
<button class="hide-id">
Hide
</button>
</p>
</div>

This is a simple solution for the functionality you want. It will need more styling to get it to look exactly the the example you provided above.
HTML
<div class="container">
<p>
<input class="patient-id-content" type="password" value="34324345">
<button id="pass-toggle" class="hide-id" onclick="toggleShowPassword()">
Show
</button>
</p>
</div>
JS
let passwordVisible = false;
function toggleShowPassword() {
let inputType = 'password';
passwordVisible = !passwordVisible;
if (passwordVisible) {
inputType = 'text';
$('#pass-toggle').addClass( "show-id" ).text( 'Hide' );
} else {
$('#pass-toggle').removeClass( "show-id" ).text( 'Show' );
}
$('.patient-id-content').attr('type', inputType);
CSS
.patient-id-content {
border: 0;
}

You could do something like:
to have hidden by default:
<span class="patient-id-content" type="text" data-patient-id="34324345" data-visible="false">********</span>
to show by default:
<span class="patient-id-content" type="text" data-patient-id="34324345" data-visible="true">34324345</span>
$('.hide-id').on('click', function () {
const patientId = $(this).prev('span'); // dependent on this DOM placement
const patientIdValue = patientId.attr('data-patient-id');
const isShowing = patientId.data('visible');
const valueToShow = isShowing ? '********' : patientIdValue;
patientId.text(valueToShow);
patientId.data('visible', !isShowing)
});
Included a JS Fiddle: https://jsfiddle.net/w7shxztp/20/

I have fixed the issue with the below solution:
$(".icofont-eye").on("click", function() {
$('#Patient-id-icon-element').toggleClass('icofont-eye-blocked');
$('#Patient-id-icon-element').toggleClass('icofont-eye');
var patientIdcontent = $(".patient-id-content");
var patientIdcontentText = patientIdcontent.text();
if (patientIdcontentText.indexOf("*")) {
$(".patient-id-content").text('***************');
} else {
$(".patient-id-content").text('3d4532403d453240');
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="row mt-1">
<div class="col-4 text-right mychart-label">Patient ID</div>
<div class="col-8 section-content">
<span class="patient-id-content">****************</span> <span class="patient-id-icon">
<a class="icofont icofont-eye cl-icon-1-point-3x mt-1" id="Patient-id-icon-element" type="button">Show</a>
</span>
</div>
</div>

How do I count divs clicked using an event listener in javascript

I'm trying the count the total number of divs clicked and exactly which ones were clicked. I'm using an event listener because the onclick is already used. Let me clarify a bit more, first, here's my code:
<div class="wrapper">
<div class="square" onclick="classList.toggle('selected')">1</div>
<div class="square" onclick="classList.toggle('selected')">2</div>
<div class="square" onclick="classList.toggle('selected')">3</div>
</div>
<div id="dis"></div>
.selected {
background: white;
}
var numClicked = document.querySelectorAll('.wrapper');
numClicked.forEach(numClicked =>
numClicked.addEventListener('click', clickedDivs)
)
function clickedDivs () {
i = 0;
numClicked.forEach(numClicked =>
i++
var x = document.getElementById("dis");
x.innerHTML = "Squares selected: " + i;
}
What I'm trying to do with my javascript is count how many divs are selected. I'm also trying to tell exactly where ones were clicked. Let's say 1 and 2 were clicked, how do I find those were clicked and total number of divs clicked using js?

What you are doing wrong here is:
You are initialising i within the onClick event fn. which will always reset the value to 0 when ever the div will be clicked.
you are not storing anywhere which div is clicked
You are adding you'r listener on wrapper instead of .square (if you are not trying to get the value of clicked wrappers instead of clicked square)
So you can modify you'r javascript like this
<style>
.square{width: 100px; height: 100px; background: grey;}
.selected {
background: white;
}
</style>
<div class="wrapper">
<div class="square" onclick="classList.toggle('selected')">1</div>
<div class="square" onclick="classList.toggle('selected')">2</div>
<div class="square" onclick="classList.toggle('selected')">3</div>
</div>
<div id="dis"></div>
<script>
var numClicked = document.querySelectorAll('.square');
numClicked.forEach(numClick => {
numClick.addEventListener('click', clickedDivs)
}
)
var itemsClicked = [] //to store which div is clicked
function clickedDivs (e) {
var value = e.target.innerHTML;
//edit
if(itemsClicked.indexOf(value) != -1) itemsClicked.splice(itemsClicked.indexOf(value), 1)
else
itemsClicked.push(value);
var x = document.getElementById("dis");
x.innerHTML = "Squares selected: " + itemsClicked.join(",");
}
</script>
edit:
added to code to remove data from the list if already exist.

Rather than attach a handler to each div, you can use 1 window event listener. Give each clickable div an id that contains "clickable" so the event listener can filter out divs you aren't tracking. When you first click a tracked div, set its id as a key within a global object and assign 1 as the value; on additional clicks, increase value by 1.
const clicks = {};
window.addEventListener("click", (e)=> {
const id = e.target.id;
if(!id.includes("clickable"))return;
clicks[id]? clicks[id] += 1 : clicks[id] = 1;
console.log(clicks);
},)
<div class="wrapper">
<div id="clickable1" class="square">1</div>
<div id="clickable2" class="square">2</div>
<div id="clickable3" class="square">3</div>
</div>

My solution, I haven't tested it yet, test it and tell me how we adjusted it.
<div class="wrapper">
<div class="square" id="d-1">1</div>
<div class="square" id="d-2">2</div>
<div class="square" id="d-3">3</div>
</div>
<div id="result"></div>
var count = [];
var wrappers = document.querySelectorAll('.wrapper');
wrappers.forEach(square => square.addEventListener('click',() => onClickwrapperSquare(square.id));
function onClickwrapperSquare(id) {
var result = document.getElementById('result');
if(count.indexOf(id) == -1){
count.push(id);
}else{
count = count.slice(count.indexOf(id)+ 1);
}
result.innerHTML = `Squares selected: ${count.length}`;
}

This can be simply achieved by jQuery.
var count;
$(".square").click(function (){
count = count+1;
$("#dis").html(count);
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="wrapper">
<div class=square">1</div>
<div class="square">2</div>
<div class="square">3</div>
</div>
<div id="dis"></div>

How to add and remove a class to a div element plain javascript

I am trying to add different classes to a div based on what is clicked, which I've managed to do, but need to remove the previously clicked/selected class and replace with the clicked one, Can't seem to get the remove part right. Most of the solutions I've come across are either toggles or adding and removing between two classes, but not 3 or more.
Thanks
This is what I have tried so far and the add part works as expected but when I click a different button it does not remove the previous clicked one
The HTML
<button id="btn-1" data-width="w-1/3">Mobile</button>
<button id="btn-2" data-width="w-2/3">Tablet</button>
<button id="btn-3" data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>
The Javascript
let setMobile = document.querySelector('#btn-1');
let setTablet = document.querySelector('#btn-2');
let setDesktop = document.querySelector('#btn-3');
let btns = [setMobile, setTablet, setDesktop];
function getBtnId(btn) {
btn.addEventListener('click', function() {
let frame = document.querySelector('.frame')
frame.classList.add(this.dataset.width)
if(frame.classList.contains(btns)){
frame.classList.remove(this.dataset.width)
}
console.log(this.dataset.width);
});
}
btns.forEach(getBtnId);
Basically, what I am trying to do is a responsive frame which will adjust its width depending on what is clicked.

You can store the current class in a variable and use the remove() to remove the previous class on each click.
let setMobile = document.querySelector('#btn-1');
let setTablet = document.querySelector('#btn-2');
let setDesktop = document.querySelector('#btn-3');
let btns = [setMobile, setTablet, setDesktop];
var currentClass;
function getBtnId(btn) {
btn.addEventListener('click', function() {
let frame = document.querySelector('.frame')
if (currentClass) {
frame.classList.remove(currentClass);
}
currentClass = this.dataset.width;
frame.classList.add(currentClass);
console.log(this.dataset.width);
});
}
btns.forEach(getBtnId);
<button id="btn-1" data-width="w-1/3">Mobile</button>
<button id="btn-2" data-width="w-2/3">Tablet</button>
<button id="btn-3" data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>

Here's a generalized version to work with multiple elements. I've wrapped each frame and buttons in a section element. Then I've bound the event listeners to the sections and used event bubbling / event delegation to perform the switch. I've also used a data attribute on the target frame to hold the current state.
function setWidthClass(event) {
var newWidth = event.target.dataset.width;
//This identifies a button click with our dataset
if (newWidth) {
//get the target div
var target = this.querySelector(".frame");
//if the target has a class set remove it
if (target.dataset.width) {
target.classList.remove(target.dataset.width);
}
//Add the new class
target.classList.add(newWidth);
//Update the data on the target element
target.dataset.width = newWidth;
}
}
//Add the event listener
var sections = document.querySelectorAll(".varyWidth");
for (var i = 0; i < sections.length; i++) {
sections[i].addEventListener("click", setWidthClass);
}
.w-third {
color: red;
}
.w-half {
color: blue;
}
.w-full {
color: green;
}
<section class="varyWidth">
<button data-width="w-third">Mobile</button>
<button data-width="w-half">Tablet</button>
<button data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>
</section>
<section class="varyWidth">
<button data-width="w-third">Mobile</button>
<button data-width="w-half">Tablet</button>
<button data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>
</section>
<section class="varyWidth">
<button data-width="w-third">Mobile</button>
<button data-width="w-half">Tablet</button>
<button data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>
</section>

Rather than track the current class, you can also just reset it:
let setMobile = document.querySelector('#btn-1');
let setTablet = document.querySelector('#btn-2');
let setDesktop = document.querySelector('#btn-3');
let btns = [setMobile, setTablet, setDesktop];
function getBtnId(btn) {
btn.addEventListener('click', function() {
let frame = document.querySelector('.frame')
// reset the classList
frame.classList = ["frame"];
frame.classList.add(this.dataset.width)
console.log(this.dataset.width);
});
}
btns.forEach(getBtnId);
<button id="btn-1" data-width="w-1/3">Mobile</button>
<button id="btn-2" data-width="w-2/3">Tablet</button>
<button id="btn-3" data-width="w-full">Desktop</button>
<div class="frame">
Some Content
</div>