Develop Reference

Shopping Cart Update Total Function doesnt work

I am building an eCommerce store website, and I am facing an issue. The function updateCartTotal doesn't work at all. The script is also added to the bottom of the HTML body.
Thanks in advance.
HTML:
<span class="material-symbols-outlined" id="cart-icon">
shopping_cart
</span>
<div class="cart">
<h2 class="cart-title">Your Shopping Cart</h2>
<div class="cart-content">
<div class="cart-box">
<img src="/Monn-Homme/images/tie1.jpg" class="cart-image">
<div class="detail-box">
<div class="cart-product-title">
Tie
</div>
<div class="cart-price"> £10.99</div>
<input type="number" value="1" class="cart-qty">
</div>
<span class="material-symbols-outlined" id="cart-remove">
delete
</span>
</div>
</div>
<div class="total">
<div class="total-title">Total</div>
<div class="total-price">£10.99</div>
</div>
<button type="button" class="buy-btn">Buy Now</button>
<span class="material-symbols-outlined" id="close-cart">
close
</span>
</div>
</div>
Javascript:
let cartIcon = document.getElementById("cart-icon");
let cart = document.querySelector(".cart");
let CloseCart = document.querySelector("#close-cart");
cartIcon.onclick = () => {
cart.classList.add("active");
};
CloseCart.onclick = () => {
cart.classList.remove("active");
};
if (document.readyState == "loading") {
document.addEventListener("DOMContentLoaded", ready);
} else {
ready();
}
function ready() {
var removeCartButtons = document.getElementsByClassName("material-symbols-outlined");
for (var i = 0; i < removeCartButtons.length; i++) {
var button = removeCartButtons[i];
button.addEventListener("click", removeCartItem)
}
// Quantity Change //
var quantitInputs = document.getElementsByClassName("cart qty");
for (var i = 0; i < quantitInputs.length; i++) {
var input = quantitInputs[i];
input.addEventListener("change", quantityChanged);
}
}
function removeCartItem(event) {
var buttonClicked = event.target;
buttonClicked.parentElement.remove();
updateCartTotal();
}
quantityChanged = (event) => {
var input = event.target;
if (isNaN(input.value) || input.value <= 0) {
input.value = 1;
}
updateCartTotal();
}
function updateCartTotal() {
var cartContainer = document.getElementsByClassName("cart-content")[0];
var cartBox = cartContainer.getElementsByClassName("cart-box");
var total = 0
for (var i = 0; i < cartBox.length; i++) {
var cartBox = cartBox[i]
var priceElement = cartBox.getElementsByClassName("cart-price")[0]
var quantityElement = cartBox.getElementsByClassName("cart-qty")[0]
price = parseFloat(priceElement.innerText.replace("£", ""))
quantity = quantityElement.value
total = total + (price * quantity)
}
document.getElementsByClassName("total-price")[0].innerText = total
}
i am expecting the total to update as the quantity changes, and the function to work

You have the following mistakes-
There is no element with the class name cart qty.
var quantitInputs = document.getElementsByClassName("cart qty");
quantityChanged function should have a function keyword.
You are using the same name variable cartBox in updateCartTotal function which is creating confusion-
var cartBox = cartContainer.getElementsByClassName("cart-box");
for (var i = 0; i < cartBox.length; i++) {
var cartBox = cartBox[i]
}
Now, after fixing these mistakes, your code will look like the below which is working.
Note- I moved all the declarations to the top and I replaced those two methods-
getElementsByClassName() = querySelectorAll()
getElementsByClassName()[0] = querySelector()
let cartIcon = document.querySelector("#cart-icon");
let cart = document.querySelector(".cart");
let CloseCart = document.querySelector("#close-cart");
var quantitInputs = document.querySelectorAll(".cart-qty");
var removeCartButtons = document.querySelectorAll(".material-symbols-outlined");
var cartContainer = document.querySelector(".cart-content");
var cartBox = cartContainer.querySelectorAll(".cart-box");
var totalEl = document.querySelector(".total-price")
cartIcon.onclick = () => {
cart.classList.add("active");
};
CloseCart.onclick = () => {
cart.classList.remove("active");
};
if (document.readyState == "loading") {
document.addEventListener("DOMContentLoaded", ready);
} else {
ready();
}
function ready() {
for (var i = 0; i < removeCartButtons.length; i++) {
var button = removeCartButtons[i];
button.addEventListener("click", removeCartItem);
}
// Quantity Change //
for (var i = 0; i < quantitInputs.length; i++) {
var input = quantitInputs[i];
input.addEventListener("change", quantityChanged);
}
}
function removeCartItem(event) {
var buttonClicked = event.target;
buttonClicked.parentElement.remove();
updateCartTotal();
}
function quantityChanged(event) {
var input = event.target;
if (isNaN(input.value) || input.value <= 0) {
input.value = 1;
}
updateCartTotal();
};
function updateCartTotal() {
var total = 0;
for (var i = 0; i < cartBox.length; i++) {
var cartBoxEl = cartBox[i];
var priceElement = cartBoxEl.querySelector(".cart-price");
var quantityElement = cartBoxEl.querySelector(".cart-qty");
price = parseFloat(priceElement.innerText.replace("£", ""));
quantity = quantityElement.value;
total = total + price * quantity;
}
if (totalEl) {
totalEl.innerText = total;
}
}
<div>
<span class="material-symbols-outlined" id="cart-icon">
shopping_cart
</span>
<div class="cart">
<h2 class="cart-title">Your Shopping Cart</h2>
<div class="cart-content">
<div class="cart-box">
<img src="/Monn-Homme/images/tie1.jpg" class="cart-image">
<div class="detail-box">
<div class="cart-product-title">
Tie
</div>
<div class="cart-price"> £10.99</div>
<input type="number" value="1" class="cart-qty">
</div>
<span class="material-symbols-outlined" id="cart-remove">
delete
</span>
</div>
</div>
<div class="total">
<div class="total-title">Total</div>
<div class="total-price">£10.99</div>
</div>
<button type="button" class="buy-btn">Buy Now</button>
<span class="material-symbols-outlined" id="close-cart">
close
</span>
</div>
</div>

Click on the button and show Alert

The following code shows an alert box:
I want each box to be displayed by clicking on its own button
html
<button class="btn-alert btn-success" type="submit">delete</button>
<button class="btn-alert btn-success" type="submit">delete</button>
<button class="btn-alert btn-success" type="submit">delete</button>
<div class="alert-s col-4"></div>
<div class="alert-s col-4"></div>
<div class="alert-s col-4"></div>
<script>
const targetDiv = document.getElementById("alert");
const btn = document.getElementById("toggle");
function clickfn() {
for(let i = 0; i < targetDiv.length; i++) {
if (targetDiv.style.display = "none") {
targetDiv.style.display = "block";
} else {
targetDiv.style.display = "none";
}
}
};
</script>
can anyone help me to do so?

You can add a class to all your buttons, lets say toggle, then use javascript to call your function like:
var btns = document.getElementsByClassName('toggles');
for (var i = 0; i < btns.length; i++) {
btns[i].onclick = function () {
alert("Finaly!");
}
}

you don't need the for loop as getElementById returns a single element.
If you want to show alert on both button click and don't want to write two separate codes give them a similar class name and query them that way using document.querySelectorAll(a dot class name in quotes).
<button class="btn">Button one</button>
<button class="btn">Button two</button>
<script>
const btns = document.querySelectorAll(".btn");
for (let i = 0; i < btns.length; i++) {
btns[i].onclick = () => {
alert(`button ${i + 1} was clicked`);
};
}
</script>

Added text strings do not show in unordered list

I'm trying to code a small application that lets you dynamically add text strings in an unordered list, but the problem is the strings I pass as input do not show up after clicking the "Invia/Send" button. I have tried with a few solutions from other questions, but none of them worked. Any ideas?
<html>
<head>
<title>Promemoria esercizi</title>
</head>
<body>
<ul id="paragraphList">
</ul>
<form id="paragraphForm">
<br></br>
<textarea id="insertParagraph" rows="5" cols="100"></textarea>
<label>Inserisci il paragrafo:
<input type="radio" id="insertType" name="InsertType" value="last">In fondo
<input type="radio" id="insertType" name="InsertType" value="before">Dietro il paragrafo
<select id="beforeParagraph"></select><br></br>
</label>
<button id="add" onclick="addParagraph(paragraphArray)">Inserisci</button><br></br>
</form>
<script>
var paragraphArray = [];
document.getElementById("paragraphList").innerHTML = paragraphArray;
function addParagraph(paragraphArray){
var text = document.getElementById("insertParagraph").value;
var radio = document.getElementById("insertType");
var selectedInsertType = "";
var ul = document.getElementById("paragraphList");
var sel = document.getElementById("beforeParagraph");
var selectedBeforeParagraph = sel.options[sel.selectedIndex].value;
for(i = 0; i < radio.length; i++){
if(radio[i].checked){
selectedInsertType = radio[i].value;
}
}
if(selectedInsertType = "last"){
paragraphArray.push(text);
}else if(selectedInsertType = "before"){
paragraphArray.splice((selectedBeforeParagraph-1), 0, text);
}
var newChoice = document.createElement("option");
newChoice.value = paragraphArray.length.toString();
newChoice.text = paragraphArray.length.toString();
for(i = 0; i < paragraphArray.length; i++){
var li = document.createElement("li");
li.innerHTML = paragraphArray[i];
}
document.getElementById("paragraphList").innerHTML = paragraphArray;
}
</script>
</body>
</html>

There were a few issues:
A common problem people run into with the button tag is by default, it has a type of 'submit' which will submit the form. There are a few ways to disable this, my preferred method is to set the type as button.
Another issue is you don't have any content in the select box, which was causing an error trying to get the value of a select box with no options that can be selected.
I updated your radios, to use querySelectorAll and look for :checked that way you don't need to create an if statement.
I also removed the paragraphArray from addParagraph() since it is a global variable.
<html>
<head>
<title>Promemoria esercizi</title>
</head>
<body>
<ul id="paragraphList">
</ul>
<form id="paragraphForm">
<br></br>
<textarea id="insertParagraph" rows="5" cols="100"></textarea>
<label>Inserisci il paragrafo:
<input type="radio" id="insertType" name="InsertType" value="last">In fondo
<input type="radio" id="insertType" name="InsertType" value="before">Dietro il paragrafo
<select id="beforeParagraph"></select><br></br>
</label>
<button type="button" id="add" onclick="addParagraph()">Inserisci</button><br></br>
</form>
<script>
var paragraphArray = [];
document.getElementById("paragraphList").innerHTML = paragraphArray;
function addParagraph(){
var text = document.getElementById("insertParagraph").value;
var radio = document.querySelectorAll("#insertType:checked");
var selectedInsertType = "";
var ul = document.getElementById("paragraphList");
var sel = document.querySelector("#beforeParagraph");
var selectedBeforeParagraph = (sel.selectedIndex > -1) ? sel.options[sel.selectedIndex].value : "";
for(i = 0; i < radio.length; i++){
selectedInsertType = radio[i].value;
}
if(selectedInsertType = "last"){
paragraphArray.push(text);
}else if(selectedInsertType = "before"){
paragraphArray.splice((selectedBeforeParagraph-1), 0, text);
}
var newChoice = document.createElement("option");
newChoice.value = paragraphArray.length.toString();
newChoice.text = paragraphArray.length.toString();
for(i = 0; i < paragraphArray.length; i++){
var li = document.createElement("li");
li.innerHTML = paragraphArray[i];
}
document.getElementById("paragraphList").innerHTML = paragraphArray;
}
</script>
</body>
</html>

use location.hash to keep page status in javascript

I am doing a practice that use location.hash to keep page's state, what i have done using the below code is
1.click any button, the button's innerHTML will be written into the div#cont
2.refresh the page, it keeps the changes in the div#cont
<body>
<button id="a">A</button>
<button id="b">B</button>
<button id="c">C</button>
<div id="cont"></div>
<script>
// var hashValue;
function getHash() {
var hashValue = location.hash;
return hashValue;
}
function draw() {
var cont = getHash();
if (cont) {
document.getElementById('cont').innerHTML = cont.slice(1);
}
}
btns = document.getElementsByTagName('button');
for (i = 0; i < btns.length; i++) {
btns[i].index = i;
btns[i].onclick = function() {
location.hash = btns[this.index].innerHTML;
}
}
window.onhashchange = function() {
draw();
}
draw();
</script>
</body>
And what i want to achieve next is add three other buttons(D,E,F) and a new div, when clicking one of the D\E\F, the innerHTMl will written into the new div.
The final goal is
click one of the A\B\C, the value will be written into 'contABC'
click one of the D\E\F, the value will be written into 'contDEF'
keep the changes when the page refresh
because this time it has to record two value, and i have no idea how to use hash to do that, anyone can help? Thanks in advance!
This is HTML:
<button id="a">A</button>
<button id="b">B</button>
<button id="c">C</button>
<button id="d">D</button>
<button id="e">E</button>
<button id="f">F</button>
<div id="contABC"></div>
<div id="contDEF"></div>

Try by structuring the way you store the hash value , like using a separator -
<body>
<button data-attr='ABC' id="a">A</button>
<button data-attr='ABC' id="b">B</button>
<button data-attr='ABC' id="c">C</button>
<button data-attr='DEF' id="d">D</button>
<button data-attr='DEF' id="e">E</button>
<button data-attr='DEF' id="f">F</button>
<div id="contABC"></div>
<div id="contDEF"></div>
<script>
// var hashValue;
function getHash() {
var hashValue = location.hash && location.hash.slice(1);
return hashValue && hashValue.split('-');
}
function draw() {
var cont = getHash();
if (cont && cont.length>0) {
document.getElementById('contABC').innerHTML = cont[0];
document.getElementById('contDEF').innerHTML = cont[1];
}
}
btns = document.getElementsByTagName('button');
var seperator = '-';
for (i = 0; i < btns.length; i++) {
btns[i].index = i;
btns[i].onclick = function() {
var cont = getHash() || [];
if(btns[this.index].dataset.attr=='ABC'){
location.hash = btns[this.index].innerHTML + seperator + cont[1];
}else{
location.hash = cont[0] + seperator + btns[this.index].innerHTML ;
}
}
}
window.onhashchange = function() {
draw();
}
draw();
</script>
</body>

Display elemens of 2 arrays in <li>

And thanks in advance for looking into this, I am trying to show elements of 2 arrays in html (li) tags. This should be the format echoed out:
array1; array2
c201;100
c202;0
c450;320
......
The elements that will be pushed into the array are coming from input fields. I have created the following code and I get to see the correct format but when I copy and paste the values above, it loses the format and instead of having two columns, it pastes elements of array2 just below the elements of array1:
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>My Web Page</title>
<script>
var array_accounts = [];
var array_credits = [];
var x = 0;
var i = 0;
var z = 0;
function spara(){
var accounts_code_str = document.getElementById('accounts').value;
var accounts_code_comma = accounts_code_str.split(' ');
var accounts_code_comma = accounts_code_comma.join(';<br>');
array_accounts.push(accounts_code_comma);
console.log(array_accounts);
var iz_credits_str = document.getElementById('credits').value;
var iz_credits_comma = iz_credits_str.split(" ");
//var iz_credits_comma = iz_credits_comma.join('<br> ');
for(var z=0; z<iz_credits_comma.length; z++){
if(iz_credits_comma[z] < 0){
iz_credits_comma[z] = 0;
}
}
var iz_credits_comma = iz_credits_comma.join('<br> ');
array_credits.push(iz_credits_comma);
showAccounts();
showCredits();
}
</script>
</head>
<body>
<h1>Accounts and IZ credits</h1>
<div id="form">
<form>
<label>Insertar Accounts codes</label>
<input type="text" name="accounts" id="accounts" />
<label>Insertar Iz credits</label>
<input type="text" name="credits" id="credits" />
<input type ="button" onclick="spara()" value="Process data" />
</form>
</div>
<div id="codes" style="float:left">
<script>
function showAccounts(){
for (var x=0;x<array_accounts.length;x++){
document.write('<div style="float:left;">'+array_accounts[x]+';</div>');
}
}
</script>
</div>
<div id="credits" style="float:left">
<script>
function showCredits(){
for (var i=0;i<array_credits.length;i++){
document.write('<div style="float:left;">'+array_credits[i]+'<br></div>');
}
}
</script>
</div>
</body>
</html>
Many thanks in advance for your help!

Hope this helps!
<script>
var array_accounts = [];
var array_credits = [];
var x = 0;
var i = 0;
var z = 0;
function spara(){
var accounts_code_str = document.getElementById('accounts').value;
array_accounts = accounts_code_str.split(' ');
console.log(array_accounts);
var iz_credits_str = document.getElementById('credits').value;
var iz_credits_comma = iz_credits_str.split(" ");
array_credits=iz_credits_comma;
//var iz_credits_comma = iz_credits_comma.join('<br> ');
for(var z=0; z<iz_credits_comma.length; z++){
if(iz_credits_comma[z] < 0){
iz_credits_comma[z] = 0;
}
}
showAccounts();
}
function showAccounts(){
var ol = document.createElement("OL");
for (var x=0;x<array_accounts.length;x++){
var li = document.createElement("LI");
var textnode = document.createTextNode(array_accounts[x]+';'+array_credits[x]);
li.appendChild(textnode);
ol.appendChild(li)
}
document.getElementById("codes").appendChild(ol);
}
</script>
Modify the two javascript functions and that should do the trick! Thanks.