Using localStorage to Remember if User Already Voted - javascript

I'm trying to use localStorage to remember if the user has already voted. I have 5 buttons — all with a unique ID to help me keep track of things.
When a user clicks on one of these buttons (e.g., button-1), I store the ID of that button with a value. So in localStorage, it looks something like this: key: button-1, value: clicked.
If the user has already clicked (voted) on that button, it needs to display a message, something like "Thank you for your vote." Otherwise it should keep that button active.
I'm struggling to do this systematically if I have multiple buttons. Do I store a separate key for each button in localStorage? Do I append them under one key? I am not sure.
My JSFiddle is here as an example with 3 buttons http://jsfiddle.net/d8kt69rp
HTML
<div id="button-1">
<button value="yes" onclick="recordFeedback(1, this);">Button 1</button>
</div>
<div id="button-2">
<button value="yes" onclick="recordFeedback(2, this);">Button 2</button>
</div>
<div id="button-3">
<button value="yes" onclick="recordFeedback(3, this);">Button 3</button>
</div>
JS
// If user has already voted, just display them a 'thanks' message
if (localStorage.getItem('button-1')) {
var div = document.getElementById('button-1');
div.innerHTML = 'Thank for your feedback';
}
// Record user feedback based on the button they clicked
function recordFeedback(id, response) {
userResponse = response.value;
var div = document.getElementById('button-' + id);
if (userResponse === 'yes') {
div.innerHTML = 'Thanks for your feedback.';
console.log('button-' + id + ' was clicked.');
localStorage.setItem('button-' +id, 'clicked');
}
}

You can do something like this:
Fiddle: http://jsfiddle.net/AtheistP3ace/d8kt69rp/2/
HTML (added class to divs):
<div class="button-div" id="button-1">
<button value="yes" onclick="recordFeedback(1, this);">Button 1</button>
</div>
<div class="button-div" id="button-2">
<button value="yes" onclick="recordFeedback(2, this);">Button 2</button>
</div>
<div class="button-div" id="button-3">
<button value="yes" onclick="recordFeedback(3, this);">Button 3</button>
</div>
JS:
// Wait for DOM to be ready
document.addEventListener('DOMContentLoaded',
function() {
document.removeEventListener('DOMContentLoaded', arguments.callee, false);
// Get all the button divs
var buttons = document.getElementsByClassName('button-div');
var index = 0, length = buttons.length;
for (; index < length; index++) {
// For each one check if it has a localStorage value
if (localStorage.getItem(buttons[index].id) == 'clicked') {
buttons[index].innerHTML = 'Thank for your feedback';
}
}
}, false
);
As for having a key for each or keeping them all together. That's personal preference. Me, I would prefer keeping them together. Feels cleaner although a little more code.
Fiddle: http://jsfiddle.net/AtheistP3ace/d8kt69rp/4/
function recordFeedback(id, response) {
userResponse = response.value;
var div = document.getElementById('button-' + id);
if (userResponse === 'yes') {
div.innerHTML = 'Thanks for your feedback.';
// Get storage and parse it to an object
var storage = JSON.parse(localStorage.getItem('userResponses'));
// If storage doesn't exist initialize it
if (!storage) storage = {};
storage['button-' + id] = 'clicked';
// Make it a string and set it
localStorage.setItem('userResponses', JSON.stringify(storage));
}
}
document.addEventListener('DOMContentLoaded',
function() {
document.removeEventListener('DOMContentLoaded', arguments.callee, false);
var storage = JSON.parse(localStorage.getItem('userResponses'));
// Don't waste time finding or looping if no votes
if (storage) {
var buttons = document.getElementsByClassName('button-div');
var index = 0, length = buttons.length;
for (; index < length; index++) {
if (storage[buttons[index].id] == 'clicked') {
buttons[index].innerHTML = 'Thank for your feedback';
}
}
}
}, false
);

Related

How to show a response when filtering through a list of elements using javascript

Hello I am creating an FAQ page that has to be filtered using javascript as below
Credit : https://makitweb.com/jquery-search-text-in-the-element-with-contains-selector/
$(document).ready(function () {
$('#filter').keyup(function () {
// Search text
var text = $(this).val().toLowerCase();
var error = document.getElementById("error");
// Hide all content class element
$('.mobrog-ux-text').hide();
// Search
$('.mobrog-ux-text').each(function () {
if ($(this).text().toLowerCase().indexOf("" + text + "") != -1) {
$(this).closest('.mobrog-ux-text').show();
setTimeout(
function () {
var x = document.getElementById("myDIV");
x.style.display = "none";
}, 4000);
error.style.display = "none";
}
else if($(this).text().toLowerCase().indexOf("" + text + "") == 0) {
error.style.display = "block";
}
});
});
});
<form align="center">
<input id="filter" onkeydown="keydownFunction()" oninput="keyPress(this.value)" class="searchfield" type="text"
name="search" placeholder="Search the help center">
</form>
<div style="color: white;padding : 10px" align="center"></div>
</div>
<div class="content2">
<h2>Frequently asked questions</h2>
<div id"pag"="id" pag""="pag" ""></div>
<div align="center" class="col-10">
<div class="mobrog-tab-container maxwidth">
<div id="myDIV" class="loader"></div>
<div class="error" id="error"> No result found!!</div>
<div id="results" class="mobrog-ux-vertical-tabs">
<div id="tar" class="mobrog-tabs">
<button data-tab="tab1" class="active">sample tab button?<span></span></button>
<button class="empty"></button>
</div>
<div class="mobrog-maincontent">
<div data-tab="tab1" class="mobrog-tabcontent active">
<div class="mobrog-ux-text">
<button class="mobrog-accordion">sample button</button>
<div class="mobrog-panel">
<p>
sample text
</p>
</div>
</div>
Which works, but then I am trying to show a message when the filtered word is not found within the list of DIVS I'm searching through on my FAQ page
I tried the below with
else if ($(this).text().toLowerCase().indexOf("" + text + "") == 0) {
//error message display
}
But then it does not work
(e.g when I type in a word which does not exist within my FAQ I want to display an error message which is in a div) and vice versa when the word is found in my FAQ page)
like the way its been used in the method of RegExp
Live search on an Div with input filter
at the moment when I type in available and unavailable words the error message appears
Please how do I effectively display a message when a filtered word is found or not found
Thanks
Expanding on my comment, this is an example of how you could implement something like this.
To reiterate - the main problem was that the error was being shown if any result didn't match instead of showing if none match
To fix that, we can add a variable outside the loop to determine if any result was matched
$(document)
.ready(function () {
$('#filter')
.keyup(function () {
// Search text
var text = $(this).val().toLowerCase();
var error = document.getElementById("error");
// storing this in a variable will reduce how many times you call the function
var $ux_texts = $('.mobrog-ux-text');
// Hide all content class element
$ux_texts.hide();
// variable to update if any match is found
var has_match = false;
// Search
$ux_texts
.each(function () {
var $this = $(this);
if ($this.text().toLowerCase().indexOf("" + text + "") === -1) {
// flip the logic so we can return early - makes for cleaner code
return;
}
$this.closest('.mobrog-ux-text').show();
setTimeout(function () {
var x = document.getElementById("myDIV");
x.style.display = "none";
}, 4000);
has_match = true;
});
// error handling
if (has_match) {
error.style.display = "none";
} else {
error.style.display = "block";
}
});
});

JS/jQuery dynamically create arrays for each BUTTON GROUP then store BUTTON DATA VALUE accordingly on click

I have 2 button groups with multiple buttons each. I can add/remove buttons' data-value to/from a global array, but I need one array for each button grup. Cannot do that, I always end up with only 1 array.
$(document).ready(function() {
// create array (need 2 arrays, actually)
var dataValueArr = [];
// on button click
$(".button-group button").click(function() {
var dataValue = $(this).data("value");
if ($(this).hasClass("selected")) {
$(this).removeClass("selected");
// remove value from array
var filteredValues = dataValueArr.filter(function(e) {
return e !== dataValue;
});
dataValueArr = filteredValues;
} else {
$(this).addClass("selected");
// add value to array
dataValueArr.push(dataValue);
}
console.log(dataValueArr);
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="button-group">
<button data-value="1">1</button>
<button data-value="2">2</button>
</div>
<div class="button-group">
<button class="selected" data-value="A">A</button>
<button data-value="B">B</button>
<button data-value="C">C</button>
</div>
One way to do it is by create the array using window[Arrayname] = [], in the example below we get the index of the buttongroup and use that combines with a string to create the name for the array.
so if you add another button group you don't have to change the jquery.
Demo
$(document).ready(function() {
// on button click
$(".button-group button").click(function() {
var btninx = $(this).closest(".button-group").index();
if (!window["dataValueArr" + btninx]) window["dataValueArr" + btninx] = [];
var dataValue = $(this).data("value");
if ($(this).hasClass("selected")) {
$(this).removeClass("selected");
// remove value from array
var filteredValues = window["dataValueArr" + btninx].filter(function(e) {
return e !== dataValue;
});
window["dataValueArr" + btninx] = filteredValues;
} else {
$(this).addClass("selected");
// add value to array
window["dataValueArr" + btninx].push(dataValue);
}
console.log(window["dataValueArr" + btninx]);
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="button-group">
<button data-value="1">1</button>
<button data-value="2">2</button>
</div>
<div class="button-group">
<button class="selected" data-value="A">A</button>
<button data-value="B">B</button>
<button data-value="C">C</button>
</div>

How to get updated input values in HTML between form Tag

I want to check if a form has changed by using pure javascript.
My plan is to take all text including html tags between the form tag, hash the string and then when I need to check if any of the values has changed, I can just rehash the form and compare them.
So I have
<form action="/Building" method="post"> <div class="row">
<div class="col-md-12">
<div class="row">
<div class="col-md-3"> Building Address </div>
<div class="col-md-2"> City </div>
<div class="col-md-1"> State </div>
<div class="col-md-2"> Zip </div>
</div>
<div class="row">
<div class="col-md-3">
<input id="bldgResult_bldg_mail_address" name="bldgResult.bldg_mail_address" type="text" value="">
</div>
<div> ...etc
<input type="submit" value="Save and Next Building »" name="action:SaveContinue" class="btn btn-info pull-right">
<input type="submit" value="Save" class="btn btn-primary pull-right" name="action:Save">
<input type="submit" value="Go To Next Building" class="btn btn-primary hash" name="action:Next">
</div>
</form>
The problem is "value" of the input fields doesn't update. I'm able to change every textbox field and the value or the inner HTML doesnt change.
Here is the code that actually hashes and gets the innerHTML
window.onload = function () {
var forms = document.getElementsByTagName("form");
var hashValue = forms[1].innerHTML.hashCode();
Array.prototype.map.call(document.getElementsByClassName("hash"), function (hObj) {
hObj.addEventListener("click", function (event) {
if (document.getElementsByTagName("form")[1].innerHTML.hashCode() == hashValue) {
return true;
}
else {
var conf = confirm("Continue to the next building WITHOUT saving? Pressing \"Okay\" will undo any pending changes." );
if(conf)
{
return true;
}
event.preventDefault();
return false;
}
});
});
};
The above block
if (document.getElementsByTagName("form")[1].innerHTML.hashCode() == hashValue) {
return true;
}
Is always returning true, because the innerHTML doesnt change, even after the textboxes have been typed in.
What can I do? Is there another way to get the text in the HTML with updated information?
You could assign an event handler to the 'input' event of each of your fields that changes a boolean flag. You then just check that flag and set it back to false after your check is complete.
For example
document.querySelectorAll("#yourForm input").forEach(input => {
input.addEventListener("input", () => {
changed = true;
});
}
/* ... */
function checkIfChanged() {
if(changed) {
// ...
}
changed = false;
}
If you also need to check for backspace you could use the keypress event instead.
You could loop though your form elements, get and concatenate the values, and then hash the values.
Update:
Here is an example using FormData (depends on browser target):
Hash Function from Here: Generate a Hash from string in Javascript/jQuery
String.prototype.hashCode = function() {
var hash = 0, i, chr;
if (this.length === 0) return hash;
for (i = 0; i < this.length; i++) {
chr = this.charCodeAt(i);
hash = ((hash << 5) - hash) + chr;
hash |= 0; // Convert to 32bit integer
}
return hash;
};
function GetFormHash() {
var hashes = [];
var forms = document.getElementsByTagName("form");
var _hash = ""
for(var i=0;i<forms.length;i++) {
var formData = new FormData(forms[i]);
for (var key of formData.keys()) {
console.log(key + "=" + formData.get(key));
_hash = _hash + key + "=" + formData.get(key);
}
hashes.push(_hash.hashCode());
console.log(_hash.hashCode());
}
return hashes;
}
There is also an onchange event for <form>. Depends on browser...
<form onchange="alert('changed')"></form>
If you use something like jQuery you could use that change() event: https://api.jquery.com/category/events/form-events/
Change will not tell you if they change the data back - so not 100% reliable. If you were open to a library like jQuery - you could possibly serialize the data https://api.jquery.com/serialize/ to keep track of changes,
One last incomplete example. You would need to update to get non "input" form elements like textarea etc. You would also have to do a bit of work to get the selected radios...
function GetFormHashOther() {
var hashes = [];
var forms = document.getElementsByTagName("form");
var _hash = ""
for(var i=0;i<forms.length;i++) {
var chill = forms[i].getElementsByTagName("input");
for (var c of chill) {
console.log(c.name + " = " + c.value);
_hash = _hash + c.name + " = " + c.value;
}
hashes.push(_hash.hashCode());
console.log(_hash.hashCode());
}
return hashes;
}

Displaying Counter on The Actual HTML Button

I have a 'like' button; and underneath the button, I can display the 'like count'.
However, I want the 'like count' value to be displayed on the actual button itself. For example, I want the button to say: "Like 5"
How can I display both text and a variable value on a button?
Maybe you can improving with this code that i did.
HTML
<form id = "form" method = "POST">
<input type = "submit" value = "Like" />
</form>
<br />
<div id = "clicks">
counter = <label id = "count">0</label> clicks !
</div>
JS
function CountOnFormSubmitEvent(form_id, _callback_)
{
var that = this, count = 0, callback = _callback_;
var form = document.getElementById(form_id);
if(form === null) { return null; }
var reset = function(){
count = 0;
};
form.addEventListener("submit", function(evt){
callback(evt, ++count, reset);
}, false);
}
//Reseting Process You can delete if you dont want it.
var counter = new CountOnFormSubmitEvent("form", function(event, count, reset_callback){
event.preventDefault();
if(count >= 10)
{
alert("Reseting the process");
reset_callback();
}
document.getElementById("count").innerHTML = count;
});
Here is the link Jsfiddle.
DEMO JSFIDDLE

HTML button with different output onclick using JavaScript

I have the following setup - http://codepen.io/anon/pen/WvjmLv?editors=100 and am trying to output text depending on which button is clicked
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button">2</button>
<button class="wrongAnswer" type="button">5</button>
<button class="right-answer" type="button">6</button>
<button class="wrong-answer" type="button">10</button>
<script>
var text;
var wrongAnswer = document.getElementsByClassName("wrongAnswer").addEventListener("click");
var rightAnswer = document.getElementsByClassName("rightAnswer").addEventListener("click");
if (wrongAnswer) {
text = "Incorrect!";
text = "Wrong!";
text = "Try Again!";
}
if (rightAnswer) {
text = "Correct!";
}
document.getElementById("answer").innerHTML = text;
</script>
</div>
<div>
<p id="answer"></p>
</div>
If the user selects the wrong answer, it should either read Wrong!, Incorrect! or Try Again! (without repeating the same text output if their next guess is also wrong)
If they get the answer right, it should just simply read Correct!
As I'm fairly new to JavaScript, I feel as though I'm a little bit off with my solution and was wanting to know how can I make this function work?
Thanks.
Easiest and fastest way to get the result you want is by adding onclick-eventhandlers to your buttons.
<button onclick="somefunction()"></button>
After that you can easily handle what should happen after that click.
In your case I would check what's in the class attribute of the button you clicked.
By doing this you can print the results to your #answer-container.
With a simple array and a global variable of which index is next you can output different "false"-messages.
var _i = 0;
var _wrongs = ['Incorrect!', 'Wrong!', 'Try Again!'];
function showResult(b) {
var res = document.getElementById('answer');
if (b.classList.contains('right-answer')) {
res.innerHTML = 'Correct'
} else {
res.innerHTML = _wrongs[_i];
_i = _i > 1 ? 0 : _i + 1;
}
}
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" onclick="showResult(this)">2</button>
<button class="wrongAnswer" onclick="showResult(this)">5</button>
<button class="right-answer" onclick="showResult(this)">6</button>
<button class="wrong-answer" onclick="showResult(this)">10</button>
</div>
<div>
<p id="answer"></p>
</div>
Demo on Codepen
Well, there are a couple things that you need to do:
You do not have a separate click handler function defined.
You need to properly add the event function to the addEventListener call.
You cannot attach an event to multiple elements at once. You need to loop over them.
Why do you have two different classes? i.e. 'wrongAnswer' and 'wrong-answer'? Please make sure that you stick with one convention.
I added an onReady() to wait for the DOM to load before accessing and adding listeners to the elements.
Addition Information
Below, I have wrapped the document.getElementsByClassName(className) call with [].slice.call(scope, [begin[, end]]) because the result of getElementsByClassName is a NodeList. You cannot treat a list like an array in JavaScript. Since I used Array.prototype.forEach to loop over the elements, they needed to transformed into an array. This is simply syntactic sugar in order to make the code look more aesthetically pleasing and readable.
This could have easily been accomplished with a for-loop:
var nodes = document.getElementsByClassName("rightAnswer");
for (var i = 0; i < nodes.length; i++) {
var el = nodes[i];
el.addEventListener('click', clickHandler);
}
Code
var wrongTextArr = ['Try Again!', 'Wrong!', 'Incorrect!'];
var guesses = 0;
onReady(function() {
// Set the number of guesses equal to the number of questions - 1.
guesses = document.querySelectorAll('.question button').length - 1;
[].slice.call(document.getElementsByClassName('wrongAnswer')).forEach(function(el) {
el.addEventListener('click', clickHandler);
});
[].slice.call(document.getElementsByClassName('rightAnswer')).forEach(function(el) {
el.addEventListener('click', clickHandler);
});
});
function clickHandler(e) {
var text = '';
var target = e.target;
var targetClass = target.className;
if (guesses < 1) {
text = 'You have reached the max number of attempts!';
} else if (targetClass === 'wrongAnswer') {
text = wrongTextArr[--guesses]; // Decrement guesses.
} else if (targetClass === 'rightAnswer') {
text = 'Correct!';
} else {
text = 'Unexpected Error!';
}
document.getElementById('answer').innerHTML = text;
}
function onReady(callback) {
var intervalID = window.setInterval(function() {
if (document.getElementsByTagName('body')[0] !== undefined) {
window.clearInterval(intervalID);
callback.call(this);
}
}, 1000);
}
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button">2</button>
<button class="wrongAnswer" type="button">5</button>
<button class="rightAnswer" type="button">6</button>
<button class="wrongAnswer" type="button">10</button>
</div>
<div>
<p id="answer"></p>
</div>
In the code above, I tried not to stray too far away from your original code, I just simply pointed out things that made your code not work and fix them with the minimalist amount of effort. Here is my solution that I would go with.
var wrongTextArr = ['Try Again!', 'Wrong!', 'Incorrect!'];
var guesses = 0;
onReady(function() {
// Set the number of guesses equal to the number of questions - 1.
guesses = document.querySelectorAll('.question button').length - 1;
addEventListeners('button[class$="Answer"]', 'click', function(e) {
document.getElementById('answer').innerHTML = getText(e.target.className.split());
});
});
function getText(classList) {
if (guesses < 1) {
return 'You have reached the max number of attempts!';
} else if (classList.indexOf('wrongAnswer') > -1) {
return wrongTextArr[--guesses]; // Decrement guesses.
} else if (classList.indexOf('rightAnswer') > -1) {
return 'Correct!';
} else {
return 'Unexpected Error!';
}
}
// Generic functions.
function addEventListeners(selector, event, listenerFn) {
[].slice.call(document.querySelectorAll(selector)).forEach(function(el) {
el.addEventListener(event, listenerFn);
});
}
function onReady(callback) {
var intervalID = window.setInterval(function() {
if (document.getElementsByTagName('body')[0] !== undefined) {
window.clearInterval(intervalID);
callback.call(this);
}
}, 1000);
}
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button">2</button>
<button class="wrongAnswer" type="button">5</button>
<button class="rightAnswer" type="button">6</button>
<button class="wrongAnswer" type="button">10</button>
</div>
<div>
<p id="answer"></p>
</div>
Lots of good answers.. Here is another approach,
HTML:
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button" onclick="checkAnswer(this)">2</button>
<button class="wrongAnswer" type="button" onclick="checkAnswer(this)">5</button>
<button class="rightAnswer" type="button" onclick="checkAnswer(this)">6</button>
<button class="wrongAnswer" type="button" onclick="checkAnswer(this)">10</button>
</div>
<div>
<p id="answer"></p>
</div>
JS:
<script>
var count = 0;
var wrongtext = ["Incorrect!", "Wrong!", "Try Again!"];
function checkAnswer(el) {
if (el.classList.contains('wrongAnswer')) {
count++;
if(count === 3)
count = 0;
alert(wrongtext[count])
}
if (el.classList.contains('rightAnswer')) {
alert('correct');
}
}
</script>
Demo:
https://jsfiddle.net/cubq361t/22/
I am not totally sure how to make it so it will say different things like "wrong" and "incorrect" but I hope this will point you in the right direction:
<!DOCTYPE html>
<html lang="en">
<body>
<div class="section">
<p>How many sides does a hexagon have?</p>
<input type="button" onClick="wrongAnswer()" value="2">
<input type="button" onClick="wrongAnswer()" value="5">
<input type="button" onClick="rightAnswer()" value="6">
<input type="button" onClick="wrongAnswer()" value="10">
<p id="text"></p>
</div>
<script>
function wrongAnswer() {
document.getElementById('text').innerHTML = "Wrong";
}
function rightAnswer() {
document.getElementById('text').innerHTML = "Correct!";
}
</script>
</body>
</html>
Here is an updated version of your code. The main issue you had was mixing up your variable and function names.
Here is a
Fiddle
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button">2</button>
<button class="wrongAnswer" type="button">5</button>
<button class="rightAnswer" type="button">6</button>
<button class="wrongAnswer" type="button">10</button>
</div>
<div>
<p id="answer"></p>
</div>
<script>
var text;
var wrongAnswers = document.getElementsByClassName("wrongAnswer");
var rightAnswers = document.getElementsByClassName("rightAnswer");
for (var i = 0; i < wrongAnswers.length; i++) {
// alert( wrongAnswers[i]);
wrongAnswers[i].addEventListener('click', printWrongAnswer);
}
for (var i = 0; i < rightAnswers.length; i++) {
rightAnswers[i].addEventListener('click', printRightAnswer);
}
function printRightAnswer() {
text = "Correct!";
printAnswer();
};
function printWrongAnswer() {
text = "Incorrect!";
text += "Wrong!";
text += "Try Again!";
printAnswer();
}
function printAnswer() {
document.getElementById("answer").innerHTML = text;
}
</script>
In addition to the answers of Mr. Polywhirl and Bellash:
If you are new to JavaScript you should try to understand how the EventBindings are working. Every binding in JavaScript is an event, so if you click somewhere the Browser will check if he will find a binding which is listening to the event "click". So its irrelevant when you bind the event but it has to be before the click. However you have to tell JavaScript which function he has to call if someone clicks your button! Thats because events are kinda "floating" in you browser scope, they are present but know one knows when they are actually be triggered but if they are getting triggered the script have to know what gets triggered or in other words: which functionality should be triggered now?
Your lines
var wrongAnswer = document.getElementsByClassName("wrongAnswer").addEventListener("click");
var rightAnswer = document.getElementsByClassName("rightAnswer").addEventListener("click");
are wrong because you never told the event "click" what functionality should be executed if the button is clicked.
The call or one type of a correct call would be:
var someFunction = function() { // DO YOUR AWESOME WORK PLS! }
var rightAnswer = document.getElementsByClassName("rightAnswer").addEventListener("click", someFunction);
and in addition to that:
I don't know how experienced you are in programming but this lines
text = "Incorrect!";
text = "Wrong!";
text = "Try Again!";
will override each other, because you are using the same variable in all 3 rows ;)
Mr. Polywhirl and Bellash posted you some good example to begin with. Try them out and try to understand them!
Hope this makes it a bit clearer!
cheers,
Sebastian
Here's a rewrite of your code, providing comments as a sort of tutorial:
Update: added random response generation.
HTML:
<div class="question">
<p>How many sides does a hexagon have?</p>
<!--
Use a common class ('answer-button' used here) for all buttons
so that clicks can be easily handled with a single listener.
Since you know any answers that aren't right are wrong, you can
simply add a 'right-answer' class for that one and leave the
others as is.
-->
<button class="answer-button" type="button">2</button>
<button class="answer-button" type="button">5</button>
<button class="answer-button right-answer" type="button">6</button>
<button class="answer-button" type="button">10</button>
</div>
<div>
<!--
Using an id is often unnecessary, so I'd switch this to a class.
Since the above buttons represent answers, using an "answer" class
on this paragraph can bring confusion, so I'd recommend using something
more accurate, such as "response".
-->
<p class="response"></p>
</div>
<!--
Generally you'll want your js in a separate file. If you include the script, whether
inline or separate, at the bottom of the body element, as you did initially, it will
automatically execute after the dom has initialized, which is good.
-->
JavaScript:
// Wrap in an immediately invoking function expression
// to keep your variables off the global scope.
(function() {
// Capture all of your response phrases in an object.
var responses = {
correct: [
"Correct!"
],
incorrect: [
"Wrong!",
"Try Again!",
"Incorrect!"
]
};
// Get the element that will display your answer.
// getElementsByClassName returns an array, so get the
// first element in the array.
var response = document.getElementsByClassName('response')[0];
// Get all of the answer buttons.
var answerButtons = document.getElementsByClassName('answer-button');
// Set a listener on each answerButton element.
for (var i = 0; i < answerButtons.length; i++) {
// Add the event listener to the element. When the event occurs,
// the checkAnswer function will run, and will be passed an event object.
answerButtons[i].addEventListener('click', checkAnswer);
}
// event is an object that is automatically passed in
// when the listener calls this function, and event.target
// is the element where the event occurred.
function checkAnswer(event) {
// initialize a variable for the message
var message;
// get the element where the event occurred
var element = event.target;
// get all classes from target element
var classes = event.target.className;
// classes will be in a space-separated string, so
// we convert that to an array
classes = classes.split(' ');
// check if a specific class is in the array
if (classes.indexOf('right-answer') >= 0) {
// if the 'right-answer' class is there, they
// clicked the right answer.
message = getRandomArrayElement(responses.correct);
} else {
// otherwise, they clicked the wrong answer
message = getRandomArrayElement(responses.incorrect);
}
// set the target element's content to the message
response.textContent = message;
}
function getRandomArrayElement(array) {
// This function picks a random element from an array and
// returns it.
// You're going to want to pick one of these array items by their
// index, so we'll set up variables to capture the lowest and
// highest possible numbers that can be used.
var min = 0;
var max = array.length - 1;
// Javascript provides random numbers using the Math.random function,
// wich gives a random float between 0 and 1. The expression below
// uses that to generate a random number within a given range - in this
// case, between min and max.
var index = Math.floor(Math.random() * (max - min + 1)) + min;
return array[index];
}
})();
I have edited your code to help you understand how you could deal with .getElementsByClassName
<div class="question">
<p>How many sides does a hexagon have?</p>
<button class="wrongAnswer" type="button">2</button>
<button class="wrongAnswer" type="button">5</button>
<button class="rightAnswer" type="button">6</button>
<button class="rightAnswer" type="button">10</button>
</div>
<div>
<p id="answer">ok</p>
</div>
<script>
var text="...",
wrongs=document.getElementsByClassName("wrongAnswer"),
rights=document.getElementsByClassName("rightAnswer"),
wrongTexts=["Incorrect","Try Again","Wrong!"],
i=0;
for(var i=0; i< wrongs.length; i++){
wrongs[i].addEventListener("click",function(e){
text = "Incorrect!";
DisplayText();
});
}
for(var i=0; i< rights.length; i++){
rights[i].addEventListener("click",function(e){
text = "Correct!";
DisplayText();
});
}
function DisplayText(){
i=i%wrongTexts.length;
text=text=="Correct"?text:wrongTexts[i++];
document.getElementById("answer").innerHTML = text;
}
</script>
Make a function first and the assign it to the buttons like
<button onclick="myFunction()">Click me</button>
<p class="demo"></p>
Then in the JS
function myFunction() {
document.getElementByClassName("demo").innerHTML = "Hello World";
}
in your pen make a function add all the logic in it and call it on button click

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