Javascript time out div - javascript

I have an alert that says you're right/wrong. I want to put a div that will appear for a few seconds instead of the alert. So when the right/wrong answer is chosen this div will appear instead of the alert. I know a timeout function would be needed but I cant seem to get it to work. I've tried a few times and nothing is working for me. Does anyone know how I would go about this?
This is the html (divs)
<div id = "your wrong">
wrong answer!
</div>
<div id = "right answer">
Right answer!
</div>
This is the javascript for the alert
function characterclicked(nr) {
if (nr == oddoneout[currentQuestionIndex].answer) {
alert("You're right!");
score+= 200;;
}
else{
alert("you are wrong it was " + oddoneout[currentQuestionIndex].characterName);
}
nextQuestion();
}

Just about the only thing you're not allowed to use in an id value in HTML is a space. :-) So we'll need to change those ids.
But then it's a simple matter of having them start off invisible (display: none), showing the relevant one (display: block), and then hiding it again after a delay via setTimeout.
document.getElementById("btnRight").onclick = function() {
show("right");
};
document.getElementById("btnWrong").onclick = function() {
show("wrong");
};
function show(id) {
var element = document.getElementById(id);
element.style.display = "block";
setTimeout(function() {
element.style.display = "none";
}, 1000); // 1000ms = 1 second
}
<div id="wrong" style="display: none">
wrong answer!
</div>
<div id="right" style="display: none">
Right answer!
</div>
<div>
<input type="button" id="btnRight" value="Show Right">
<input type="button" id="btnWrong" value="Show Wrong">
</div>

I will hope help you
var score = 0;
var oddoneout = Array();
oddoneout[0] = {answer: "2"};
var currentQuestionIndex = 0;
var btnReply = document.getElementById("reply");
btnReply.onclick = function(){
var answer = document.getElementById("answer").value;
characterclicked(answer);
};
function characterclicked(nr) {
var feedback = document.getElementById("right_answer");
if (nr == oddoneout[currentQuestionIndex].answer) {
score+= 200;
}else{
//alert("you are wrong it was " + oddoneout[currentQuestionIndex].characterName);
feedback = document.getElementById("your_wrong");
}
feedback.style.display = "block";
setTimeout(function(){
feedback.style.display = "none";
}, 2000);
//nextQuestion();
}
.feedback {
display: none;
color: red
}
<div class="question">
how many is 1 + 1 ?
</div>
<input type="text" id="answer" />
<input type="button" id="reply" value="reply" />
<div id = "your_wrong" class="feedback">
wrong answer!
</div>
<div id = "right_answer" class="feedback">
Right answer!
</div>

First thing you should do is to make the element that will contain the message invisible. You can do this by using display: none, either in the element's style attribute or in a CSS style sheet (preferred).
Next, we'll craft a function that shows the message. Since it can show either one of two messages, it will take an argument, so it knows whether to show "right" or "wrong".
function showMessage(right) { ... }
The right argument can be a boolean to keep it simple. From here, we can use only a single <div> and change it's text according to whether or not right is true.
Let's give it an id of message (you were using spaces in your IDs, which you cannot do).
function showMessage(right) {
var text = "You are ";
text += right? "right" : "wrong";
// Let's get the result <div>
var messageDiv = document.getElementById("message");
// and change it's text
messageDiv.innerText = text;
}
Now, all that's left is to show the message <div>, and after a few seconds make it disappear again. Let's use 5 seconds for this example. 5 seconds are 5000 milliseconds, which is what the timeout functions use as a unit.
function showMessage(right) {
var text = "You are ";
text += right? "right" : "wrong";
// Let's get the result <div>
var messageDiv = document.getElementById("message");
// and change it's text
messageDiv.innerText = text;
// and show it, and hide it after 5 seconds
messageDiv.style.display = "block";
setTimeout(function(){
messageDiv.style.display = "none";
}, 5000);
}
And that's it! If you call the function with true as an argument, it will show you "You are right". Otherwise, it will show you "You are wrong".
Here's a Jsfiddle for you to see it working.
Edit
If you also want to show the correct answer when the user is wrong, you can do so with a second argument:
function showMessage(right, answer) {
var text = "You are ";
text += right? "right!" : "wrong. The answer was " + answer;
...
}

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";
}
});
});

How to hide and visible the text content based on some value?

How to write HTML and Javascript code.
I have two text content like(Hi, Hlo how are you)& (I'm 5n what about you?).
When the values comes 3 need to show 1st content(Hi, hlo how are you).
If does not come value 3 need to show second content(l'm 5n what about you)..
Thanks.
Your question is too broad to understand, where does this value come from? Is these text in same element or two different element? what you need covering few show hide use here:
Input from API call, with two div for two output:
HTML:
<div id="when3" class="hide">Hi, hlo how are you</div>
<div id="not3" class="hide">l'm 5n what about you</div>
CSS:
/* Hide block */
.hide {
display: none
}
JS:
let value = 3; //use user input here
function show() {
if (value === 3) {
document.getElementById("when3").classList.remove("hide");
document.getElementById("not3").classList.add("hide");
} else {
document.getElementById("not3").classList.remove("hide");
document.getElementById("when3").classList.add("hide");
}
}
show();
When need to change value of same element based upon some input, no two different element:
HTML:
<div id="output"></div>
JS:
let value = 3; //use user input here
function show() {
if (value === 3) {
document.getElementById("output").innerHTML = "Hi, hlo how are you";
} else {
document.getElementById("output").innerHTML = "l'm 5n what about you";
}
}
show();
Show/Hide HTML <div> based upon some clicks. Used for navigation.
HTML:
<ul>
<li onclick="show('profile')">Profile</li>
<li onclick="show('friends')">Profile</li>
<li onclick="show('messages')">Profile</li>
</ul>
<div id="profile" class="hide">Profile Details</div>
<div id="friends" class="hide">Friends</div>
<div id="messages" class="hide">Messages</div>
CSS:
/* Hide block */
.hide {
display: none
}
JS:
function show(id) {
hideAll();
let element = document.getElementById(id);
element.classList.remove("hide");
}
function hideAll() {
document.getElementById("profile").classList.add("hide");
document.getElementById("friends").classList.add("hide");
document.getElementById("messages").classList.add("hide");
}
HTML:
<div id="sample"></div>
JS:
var test = document.getElementById("sample");
var value;
if(value === 3){
test.innerHTML = "Hi, hlo how are you";
}
else{
test.innerHTML = "l'm 5n what about you";
}
html
<input type="text" id="txt"/><br/>
<input type="button" name="go" onClick="result()" value="send"/><br/>
<div id="msg"> </div>
javascript
function result(){
var test = document.getElementById("msg");
var value=document.getElementById("txt");
if(value === 3)
{
test.innerHTML = "Hi, Hlo how are you";
}
else
{
test.innerHTML = "l'm 5n what about you";
}
}
Something like this should work
function showText(val, id) {
document.getElementById(id).innerHTML = val == 3 ? "Hi, Hlo how are you" : "l'm 5n what about you";
}
showText(3, 'text');
showText(4, 'text1');
<div id="text"></div>
<div id="text1"></div>

Replace previously generated content in Javascript based on user input

I have a button on that perfroms the collatz conjecture with the push of a button, and takes in the user's input. It then prints out the steps as a list into a p tag. I wanted to know how I would override the previously created steps, as I have noticed calling the method again adds to the end of the previous list.
The main reason I'm using a list is for readability, so I don't want to get rid of it unless there's a better way of doing this.
//collatz function
function collatz (){
var step = 0;
var inputCollatz = prompt("What number do you want to add?")
if (inputCollatz <= 1){
document.getElementById("collatz").innerHTML = "No steps required, already less than or equal to 1.";
}
else if(isNaN(inputCollatz)){
document.getElementById("collatz").innerHTML = "Please add a number.";
}
else if (inputCollatz.toString().indexOf('.') != -1){
document.getElementById("collatz").innerHTML = "Whole numbers please!";
}
else{
while(inputCollatz > 1){
//needed help w/ ternary operators, still need practice with it
inputCollatz = inputCollatz % 2 ? 3 * inputCollatz + 1 : inputCollatz / 2;
step++;
var item = document.createElement("li");
var text = document.createTextNode(inputCollatz);
item.appendChild(text);
var list = document.getElementById("collatz");
list.appendChild(item);
}
document.getElementById("steps").innerHTML = "Number of steps: " + step.toString();
}
}
This is the button in html.
<button onclick="collatz()">Find the number of steps.</button><br/>
<br/>
<div id="collatz"></div>
<br/>
<div id="steps"></div>
I was suggested to clear out the collatz div before each loop, which worked.
...
else {
document.getElementById("collatz").innerHTML = '';
while(inputCollatz > 1) {
....

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

HTML/javascript TypeError when using document.getElementById even though ID's are declared

A button on my webpage stops working every few days and then starts working again without any intervention/modifying source code. This "Next" button calls a javascript function to iterate forward through an array of text already retrieved via php, but sometimes it stops working. I have not touched this code for more than a month, and during this time I have seen it working most of the time - but not always. Today it's not working.
Here is the button declaration:
<input type="button" value="Next Question" class="button" onclick="submitform('Next')" style=" padding: 0.25em 1em 0.25em 1em;" id="nextQButton"/>
The button calls function submitForm with parameter "Next."
function submitform(x)
{
document.getElementById("alertShow").innerHTML = ""
if(x=='Back')
{
....
}
else if(x=='Next')
{
alert("next Q!");
if(jj+1<numQQ){
runningSum += qnumans_array[jj];
}
++jj;
++j;
kk=0;
if (jj == limit)
{
if((viewQ==null)&&(viewA==null))
{
window.location="judge.php?counter="+j;
}
else if(viewQ)
{
window.location="judge.php?&counter="+j+"&viewQ="+viewQ;
}
else if(viewA)
{
window.location="judge.php?&counter="+j+"&viewA="+viewA;
}
}
alert("middle of next q bit1");
if( jj>=numQQ && jj!=limit)
{
--jj;
--j;
alert("middle of next q bit if statement");
document.getElementById("alertShow").innerHTML = "end of available questions for this category";
}
alert("middle of next q bit2");
alert("jj is"+jj);
alert("qid array at jj is"+qid_array[jj]);
document.getElementById('qidInput').value = qid_array[jj]; ///*****this is where it stops outputting script alerts. all alerts before this output as they should.
***********************************************
alert("middle of next q bit3");
document.getElementById('jjInput').value = j;
alert("middle of next q bit4");
document.getElementById("questionShow").innerHTML = quser_array[jj] + ": "+ question_array[jj];
alert("middle of next q bit5");
if(qnumans_array[jj]>0)
{
document.getElementById("answerShow").innerHTML = auser_array[kk + runningSum] + ": " + answer_array[kk + runningSum];
}
else
{
document.getElementById("answerShow").innerHTML = "No answers posted to this question.";
}
alert("got to end of next q bit");
}
....
}
The line after which the alerts fail relates to this input field in an html form in the same php files:
<input type = 'hidden' id = 'qidInput' name = 'qid' >
Chrome debugging tool gives me this error
Uncaught TypeError: Cannot set property 'value' of null
on every line that calls:
document.getElementById("qidInput").value = qid_array[jj];
Even though these similar calls generate no error:
document.getElementById("jjInput").value = j;
document.getElementById("kkInput").value = kk+runningSum;
All these HTML elements are declared together and are of the same type:
<form name="messageInput" id = 'idForm' method="get" action="judge.php?"
onSubmit="return validate(this)">
<center><textarea name='text' style="height: 1em"></textarea><br>
<input type = 'hidden' id = 'qidInput' name = 'qid' >
<input type = 'hidden' id = 'jjInput' name = 'counter' >
<input type = 'hidden' id = 'kkInput' name = 'kk' >
<ul class="actions">
<li><input type="submit" value="Post Message" class="button"/></li>
</ul>
</center>
</form>
If I comment out every line that contains qidInput, the error message switches to giving the same error, now for every line that contains "jjInput." So it seems to be something about the ordering - whichever HTML element is called by id first is nil.
This happens on the same computer and browser on different days. The conditions on the webpage are the same, too.
Any debugging advice would be appreciated. Thank you.
Fixes that didn't work:
-swapping single and double quotes
-adding a "dummy" element and setting it first (so it's probably not ordering)

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