First I'd like to say that i'm a very new beginner when it comes to java script with no other skills involved. I seem to be a little lost in my coding. I have two sets of options with three choices within each. Each choice has its own price. How do I calculate a total price?
JavaScript (included in HEAD)
var theForm = document.forms["pizzaOrder"];
var pizza_price = new Array();
pizza_price["meatLover"] = 15.50;
pizza_price["veggieLover"] = 12.50;
pizza_price["supreme"] = 20.00;
function getPizzaPrice() {
var pizzaPrice = 0;
var theForm = document.forms["pizzaOrder"]; //You already declared "theForm" at global scope - no need to redeclare it here to hold the same reference -crush
var pizzaType = theForms.elements["pizzaType"]; //Mispelled "theForm" here -crush
for(var i = 0; i < pizzaType.length; i++) {
if(pizzaType[i].checked) {
pizzaPrice = pizza_price[pizzaPrice[i].value];
break;
}
}
return pizzaPrice;
}
var extra_top = new Array()
extraTop["extraChees"] = 1.00;
extraTop["mushrooms"] = 1.10;
extraTop["anchovies"]-1.25; //Obvious syntax error here -crush
function getToppingPrice() {
var toppingPrice=0;
var theForm = document.forms["pizzaOrder"];
var extraTop = theForm.elements["extraTop"] //You forgot the semi-colon here -crush
for(var i = 0; i < extraTop.length; i++) {
if(extraTop[i].checked) {
toppingPrice = extra_top[extraTop.value];
break;
}
}
return toppingPrice;
}
function getTotal() //You're missing an opening bracket here -crush
var pizzaPrice = getPizzaPrice() + getToppingPrice();
document.getElementbyId('totalPrice').innerHTML = "Total Price for Pizza is $" + pizzaPrice;
//You're missing a closing bracket here -crush
HTML
<body onload="hideTotal">
<h1>Pizza To Go</h1>
<h2>Order Online</h2>
<form action="" id="PizzaOrder" onsubmit="return false;">
<p>Select Your Pizza!<br />
<input type="radio" name="pizzaType" value="meatLover" onclick="calculateTotal()"/> Meat Lover $12.50<br />
<input type="radio" name="pizzaType" value="veggieLover" onclick="calculateTotal()"/> Veggie Lover $12.50<br />
<input type="radio" name="pizzaType" value="supreme" onclick="calculateTotal()"/> Supreme $12.50<br />
<p>Add Extra Toppings!<br />
<input type="checkbox" name="extraTop" value="extraCheese" onclick="calculateTotal()"/> Extra Cheese $1<br />
<input type="checkbox" name="extraTop" value="mushrooms" onclick="calculateTotal()"/> Mushrooms $1.10<br />
<input type="checkbox" name="extraTop" value="anchovies" onclick="calculateTotal()"/> Anchovies $1.25<br />
</form>
</body>
I'm currently lost as it just doesnt seem to work. Any help is much appreciated.
Your code could stand to be cleaned up quite a bit in general, but your functional issue is that you should be using an object instead of arrays to hold your item prices. Cleanup notwithstanding, try something like this:
var pizza_price = {
"meatLover": 15.50,
"veggieLover": 12.50,
"supreme": 20.00
};
var extra_top = {
"extraChees": 1.00,
"mushrooms": 1.10,
"anchovies": -1.25
};
function getPizzaPrice() {
var pizzaPrice=0;
var theForm = document.forms["pizzaOrder"];
var pizzaType = theForms.elements["pizzaType"];
for(var i = 0; i < pizzaType.length; i++) {
if(pizzaType[i].checked) {
pizzaPrice += pizza_price[pizzaPrice[i].value];
}
}
return pizzaPrice;
}
function getToppingPrice() {
var toppingPrice=0;
var theForm = document.forms["pizzaOrder"];
var extraTop = theForm.elements["extraTop"];
for(var i = 0; i < extraTop.length; i++) {
if(extraTop[i].checked) {
toppingPrice += extra_top[extraTop[i].value];
}
}
return toppingPrice;
}
function getTotal() { return getPizzaPrice() + getToppingPrice(); }
If you want to create a jsfiddle I'll take a closer look.
Related
Looking for the simplest implementation of the following problem:
I have a user input number field like:
<input type="number" id="numInput" name="numInput" value="1" onchange="myFunc()">
<div id="demo">*** TEST ***</div>
I want to replicate the #demo div based on the #numInput value entered by the user, e.g. if the user enters '5', there would be five #demo divs displayed on the page. At the moment, I'm using the following function:
function myFunc() {
var newArray = [];
var numInput = document.getElementById('numInput').value;
var x = document.getElementById('demo').innerHTML;
for(var i=0; i<numInput; i++) {
newArray.push(x);
}
document.getElementById('demo').innerHTML = newArray;
}
but this is adding to the existing array rather than outputting the exact number of divs based on user input. Please advise. Thanks.
There should not be multiple same id values.
function myFunc() {
let numInput = document.getElementById("numInput");
while (numInput.nextSibling) {
numInput.nextSibling.remove();
}
let numInputval = document.getElementById('numInput').value;
for(var i=numInputval; i>0; i--) {
var newDiv = document.createElement('div');
newDiv.setAttribute('id', 'demo' + i);
newDiv.innerHTML = '*** TEST ***';
numInput.parentNode.insertBefore(newDiv, numInput.nextSibling);
}
}
<input type="number" id="numInput" name="numInput" onchange="myFunc()">
+Edit
You can also manipulate <form> with javascript.
function myFunc() {
let numInput = document.getElementById("numInput");
while (numInput.nextSibling) {
numInput.nextSibling.remove();
}
let numInputval = document.getElementById('numInput').value;
for(var i=numInputval; i>0; i--) {
var newInput = document.createElement('input');
newInput.setAttribute('id', 'demoInput' + i);
newInput.setAttribute('type', 'text');
newInput.setAttribute('name', 'demoInputName' + i);
newInput.setAttribute('onchange', 'myFormChangeListener(this)');
numInput.parentNode.insertBefore(newInput, numInput.nextSibling);
numInput.parentNode.insertBefore(document.createElement('br'), numInput.nextSibling);
}
}
function myFormChangeListener(element) {
console.log(element);
console.log(element.value);
myForm.action = 'http://the.url/';
myForm.method = 'post';
console.log(myForm);
//myForm.submit;
}
<form id="myForm">
<input type="number" id="numInput" name="numInput" onchange="myFunc()">
</form>
I am new to learning javascript and apologize if this question is too basic. I have tried to search for a solution but nothing has been clear to me. I have created this code in this link.
https://jsfiddle.net/5p7wzy9x/3/
var btn = document.getElementById("calc");
btn.addEventListener("click", function() {
var total = 0;
var count = 0;
var values = document.getElementsByClassName("value");
for (var i = 0; i < values.length; i++) {
var num = parseFloat(values[i].value);
if (!isNaN(num)) {
total += num;
count++;
}
}
output = total / count;
var totalTb = document.getElementById("total");
totalTb.value = count ? output : "NaN";
});
var btn = document.getElementById("calcTwo");
btn.addEventListener("click", function() {
var total = 0;
var count = 0;
var values = document.getElementsByClassName("value");
for (var i = 0; i < values.length; i++) {
var num = parseFloat(values[i].value);
if (!isNaN(num)) {
total += num;
count++;
}
}
output = (total / count);
var totalTb = document.getElementById("total");
totalTb.value = output >= 90 ? "A"
: output >= 80 ? "B"
: output >= 70 ? "C"
: output >= 60 ? "D"
: "YOU FAIL!";
});
My question is, how would I go about being able to use the same code for the second "grade" button without having to copy and pasting the same code?
I saw that you can use functions to invoke the same code block but am confused how I would go about it. I apologize if this question has already been answered, but I have diligently searched and tried to figure this out on my own. Thank you in advanced.
Instead of passing anonymous functions (functions with no names) to your event handlers as data:
btn.addEventListener("click", function() { ...
set up those functions as "function declarations" so that you can call them by name. Then, instead of passing them into the .addEventListner() method call, you reference them by name (without parenthesis next to the name).
Here's an example:
// Both buttons are configured to call the same event handling function:
document.getElementById("btn1").addEventListener("click", doSomething);
document.getElementById("btn2").addEventListener("click", doSomething);
function doSomething(){
console.log("Hello!");
}
<input type=button id="btn1" value="Click Me">
<input type=button id="btn2" value="Click Me">
Here is how you can combine common code in one function:
var btn = document.getElementById("calc");
var btn2 = document.getElementById("calcTwo");
var totalTb = document.getElementById("total");
btn.addEventListener("click", function() {
var output = getTotal();
totalTb.value = output < Infinity ? output : "NaN";
});
btn2.addEventListener("click", function() {
var output = getTotal();
totalTb.value = output >= 90 ? "A"
: output >= 80 ? "B"
: output >= 70 ? "C"
: output >= 60 ? "D"
: "YOU FAIL!";
});
function getTotal() {
var total = 0;
var count = 0;
var values = document.getElementsByClassName("value");
for (var i = 0; i < values.length; i++) {
var num = parseFloat(values[i].value);
if (!isNaN(num)) {
total += num;
count++;
}
}
output = total / count;
return output;
}
<form id="form1">
<input class="value" type="text" value="80" /><br />
<input class="value" type="text" value="50" /><br />
<input class="value" type="text" value="15" /><br />
<input class="value" type="text" value="30" /><br />
<input class="value" type="text" value="90" /><br />
<br />
<input type="text" id="total" />
<button type="button" id="calc">Calculate</button>
<button type="button" id="calcTwo">Grade</button>
</form>
UPDATE 6-25-2014
Any insight would be appreciated!
UPDATE 6-21-2014
I tried to make the radio variables, global so the 'if block' in the 'answerFwd' function could be compared to the correctAnswer Array, but that didn't work!
UPDATE 6-16-2014
ADDED JS FIDDLE
I am building a quiz and creating an array of radio buttons dynamically, and would like to match the selected button with the correct answer I have established in the question array.
html
<div id="responses">
<input type="radio" name="choices" class="radioButtons" value="0" id="choice0">
<div id="c0" class="choiceText">The Observers</div>
<input type="radio" name="choices" class="radioButtons" value="1" id="choice1">
<div id="c1" class="choiceText">The Watchers </div>
<input type="radio" name="choices" class="radioButtons" value="2" id="choice2">
<div id="c2" class="choiceText">The Sentinels</div>
<input type="radio" name="choices" class="radioButtons" value="3" id="choice3">
<div id="c3" class="choiceText">The Oa</div>
</div>
questions:
var allQuestions = [{
"question": "Who was Luke's wingman in the battle at Hoth?",
"choices": ["Dak", "Biggs", "Wedge", "fx-7"],
"correctAnswer": 0 }, {
"question": "What is the name of Darth Vader's flag ship?",
"choices": ["The Avenger", "Devastator ", "Conquest", "The Executor"],
"correctAnswer": 3 },{},{} //other questions];
var item = allQuestions[0];
var currentQuestion = 0;
var playersScore = 0;
//function which creates the buttons
function createRadioButtonFromArray(array) {
var len = array.length;
var responses = document.getElementById("responses");
responses.innerHTML = '';
for (var i = 0; i < len; i++) {
radio = document.createElement("input"); //Updated 6-21-2014 removed 'var'
radio.type = "radio";
radio.name = "choices";
radio.className = "radioButtons";
radio.value = i;
radio.id = "choice" + i;
ar radioText = document.createElement("div");
radioText.id = "c" + i;
radioText.className = "choiceText";
radioText.innerHTML = array[i];
responses.appendChild(radio);
responses.appendChild(radioText);
}
}
function answerFwd() {
var answerOutput = " ";
var itemAnswers = allQuestions;
var playerTally = 0; //Updated 6-9-2014
var playerFeedback = " "; //Updated 6-9-2014
var playerMessage = document.getElementById("playerMessage"); //Updated 6-9-2014
if (currentAnswer <= itemAnswers.length) {
currentAnswer++;
}
createRadioButtonFromArray(itemAnswers[currentQuestion].choices);
* Updated 6-9-2014 I am stumped; This doesn't work but I was encouraged I got a score tally on the page! Am I comparing the elements correctly? Updated 6-21-2014 This reversed the gain, where I had the tally render on the screen*
if (itemAnswers.correctAnswer === responses.id) { //Updated 6-21-2014
playerTally += 1;
playerFeedback += "<h5>" + playerTally + "</h5> <br/>";
playerMessage.innerHTML = playerFeedback;
}
}
At first I tried to debug this but had trouble finding where the error was coming from.
One thing I noticed was currentAnswer variable was only being set once. (when it was declared)
Another thing that would make this cleaner is storing each response to each question as a property of the questions object.
For example: {"question": "What is the registry of the Starship Reliant?","choices": ["NX-01", "NCC-1864", "NCC-1701", "NCC-2000"],"correctAnswer": 1,"selectedAnswer": 0}
This is a good example of why you may want to use object oriented programming. You can keep the global namespace clean, while also having tighter control over your variables.
I put together this Quiz Code using some object oriented principles:
JavaScript
var Quiz = function(questions) {
this.questions = questions;
this.$template = {
"header": document.querySelector(".question"),
"options": document.querySelector(".question-choices")
};
this.init();
}
Quiz.prototype = {
"init": function() {
this.question = 0;
this.generateQuestion();
this.bindEvents();
},
//gets called when this.question == this.questions.length, calculates a score percentage and alerts it
"score": function() {
var correctCount = 0;
this.questions.forEach(function(question){
if ( (question.selectedAnswer || -1) === question.correctAnswer ) correctCount += 1
})
alert("Score: " + ((correctCount / this.questions.length) * 100) + "%")
},
//Gets called during initialization, and also after a nav button is pressed, loads the question and shows the choices
"generateQuestion": function() {
var question = this.questions[this.question];
this.$template.header.innerHTML = question.question;
this.$template.options.innerHTML = "";
question.choices.forEach(this.createRadio.bind(this));
},
//Binds the previous, and next event handlers, to navigate through the questions
"bindEvents": function() {
var _this = this,
$nextBtn = document.querySelector(".question-navigation--next"),
$prevBtn = document.querySelector(".question-navigation--prev");
$nextBtn.addEventListener("click", function(e) {
//Go to the next question
_this.question++;
if ( _this.question == _this.questions.length ) {
_this.score();
} else {
_this.generateQuestion();
}
});
$prevBtn.addEventListener("click", function(e) {
_this.question--;
if ( _this.question <= 0 ) _this.question = 0
_this.generateQuestion();
});
},
//Create each individual radio button, is callback in a forEach loop
"createRadio": function(choice, index) {
var question = this.questions[this.question];
var radio = document.createElement("input");
radio.type = "radio";
radio.name = "options";
radio.id = "option-"+index;
if ( question.selectedAnswer === index ) {
radio.checked = true;
}
radio.addEventListener("click", function(e) {
question.selectedAnswer = index;
})
var radioText = document.createElement("label");
radioText.setAttribute("for", "option-"+index)
radioText.innerHTML = choice;
radioText.insertBefore(radio, radioText.firstChild);
this.$template.options.appendChild(radioText);
}
}
var q = new Quiz(allQuestions)
I am trying to design a menu. If you check a box, then sum get added up and if you uncheck it, the sum is reduced. I face trouble in reducing the sum while unchecking the box and also the value of sum is not globally changed. Please help me out.
<head>
<script>
var sum=0;
function a(sum,num) {
sum=sum+num;
document.getElementById("demo").innerHTML=sum;
}
</script>
</head>
<body>
<input type="checkbox" name="Dal" id="dal" onclick=a(sum,10)>Dal<br>
<input type="checkbox" name="Rice" id="rice" onclick=a(sum,20)>Rice<br>
<h1> Total Price is : </h1>
<p id="demo"> 0 </p>
</body>
Change the markup, add a value and a class, and remove the inline JS
<input type="checkbox" name="Dal" id="dal" value="10" class="myClass">Dal
<input type="checkbox" name="Rice" id="rice" value="20" class="myClass">Rice
<h1> Total Price is : </h1><p id="demo">0</p>
Then do
<script type="text/javascript">
var inputs = document.getElementsByClassName('myClass'),
total = document.getElementById('demo');
for (var i=0; i < inputs.length; i++) {
inputs[i].onchange = function() {
var add = this.value * (this.checked ? 1 : -1);
total.innerHTML = parseFloat(total.innerHTML) + add
}
}
</script>
FIDDLE
You can do something like this:
function a (elem, num) {
var k = (elem.checked) ? 1 : -1;
sum = sum + k * num;
document.getElementById("demo").innerHTML = sum;
}
And in the HTML:
<input type="checkbox" name="Dal" id="dal" onclick="a(this, 10);">Dal<br>
<input type="checkbox" name="Rice" id="rice" onclick="a(this, 20);">Rice<br>
Try something like this:
var sum = 0;
function a(id, num) {
if(id.checked == true){
sum += num;
id.onclick = function() { a(id, num)};
}
else {
sum -= num;
id.onclick = function() { a(id, num)};
}
document.getElementById("demo").innerHTML=sum;
}
Fiddle: http://jsfiddle.net/95pvc/2/
My own take would involve removing the event-handling from the HTML (unobtrusive JavaScript) for easier maintenance in future, using data-* attributes to contain the price and using a class-name to identify the relevant ingredients, to give the following HTML:
<input class="ingredients" type="checkbox" name="Dal" data-price="10" id="dal" />Dal
<input class="ingredients" type="checkbox" name="Rice" data-price="20" id="rice" />Rice
<h1> Total Price is : </h1>
<p id="demo">0</p>
Which leads to the following JavaScript:
var ingredients = document.getElementsByClassName('ingredients');
function price() {
var result = document.getElementById('demo'),
curPrice = 0,
ingredients = document.getElementsByClassName('ingredients');
for (var i = 0, len = ingredients.length; i < len; i++) {
if (ingredients[i].checked) {
curPrice += parseFloat(ingredients[i].getAttribute('data-price'));
}
}
result.firstChild.nodeValue = curPrice;
}
for (var i = 0, len = ingredients.length; i < len; i++) {
ingredients[i].addEventListener('change', price);
}
JS Fiddle demo.
To avoid having to iterate through the relevant checkboxes, it might be better to wrap those input elements in a form, and then bind the event-handling to that form:
var ingredients = document.getElementsByClassName('ingredients');
function price() {
var result = document.getElementById('demo'),
curPrice = 0,
ingredients = document.getElementsByClassName('ingredients');
for (var i = 0, len = ingredients.length; i < len; i++) {
if (ingredients[i].checked) {
curPrice += parseFloat(ingredients[i].getAttribute('data-price'));
}
}
result.firstChild.nodeValue = curPrice;
}
document.getElementById('formID').addEventListener('change', price);
JS Fiddle demo.
References:
addEventListener().
element.getAttribute().
getElementsByClassName().
parseFloat().
I must admit, I don't know much about JavaScript that is why my question might sound little bit silly.
But what I'm trying to do is grab values from selected by name radio groups.
It looks like this
function calc() {
var op1 = document.getElementsByName('form[radio1]');
var op2 = document.getElementsByName('form[radio2]');
var op3 = document.getElementsByName('form[radio3]');
var result = document.getElementById('result');
result.value = 0;
result.value = parseInt(result.value);
for (i = 0; i < op1.length; i++) {
if (op1[i].checked) result.value = parseInt(result.value) + parseInt(op1[i].value);
}
for (i = 0; i < op2.length; i++) {
if (op2.options[i].selected) result.value = parseInt(result.value) + parseInt(op2[i].value);
}
for (i = 0; i < op3.length; i++) {
if (op3.options[i].selected) result.value = parseInt(result.value) + parseInt(op3[i].value);
}
return false;
}
And this is my form. Im using rs form for joomla.
<form action="index.php" enctype="multipart/form-data" id="userForm" method="post">
<input name="form[radio1]" value="25" id="radio20" type="radio">
<label for="radio20">Description1</label>
<input name="form[radio1]" value="35" id="radio21" type="radio">
<label for="radio21">Description2</label>
<input name="form[radio2]" value="20" id="radio20" type="radio">
<label for="radio20">Description1</label>
<input name="form[radio2]" value="30" id="radio21" type="radio">
<label for="radio21">Description2</label>
<input type="hidden" value="0" id="result" name="form[result]">
<input type="submit" class="rsform-submit-button" onclick="calc()" id="submit" name="form[submit]" value="submit">
And everything would be OK, as the function is working. the only trouble is that I have about 80 radiograms.
Is there a way to shorten it?
Use arrays of objects (like all the radio buttons, for instance) and iterate over them. Start like this:
var opts = [],
numOpts = 80;
for (var i=0; i<numOpts, i++)
{
opts.push(document.getElementsByName('form[radio' + i + ']'));
}
Edit: let's have a go at the full function. The only thing I'm not 100% sure about is whether you mean to use opX[i].checked or opX.options[i].selected (since your code does different things for op1 and op2/3). Shouldn't be too hard to extrapolate if I've guessed wrong, though.
function calc()
{
var opts = [],
numOpts = 80,
value = 0,
result = document.getElementById('result'),
i, j, opt;
for (i=0; i<numOpts; i++)
{
opts.push(document.getElementsByName('form[radio' + i + ']'));
}
numOpts = opts.length;
for (i=0; i<numOpts; i++)
{
opt = opts[i];
for (j=0; j<opt.length; j++)
{
// or did you mean:
// if (opt.options[j].selected) ?
if (opt[j].checked)
{
value = value + parseInt(opt[j].value, 10);
}
}
}
result.value = value;
return false;
}
jQuery is a great library that's like using JavaScript on steroids. It is well worth learning and there are plenty of examples out in the wild.
You can write complex "selectors" quite like this:
$('input[name=form[radio1]]').attr('checked').each(function() {
result.value = $(this).attr('value')
})
(I'm not sure if it will accept a name like "form[radio1]" as valid, but give it a try.