I am new to JavaScript and need some help.
I am creating a sudoku gameboard using multiple buttons. I want to draw/color the border of every third line and every third column, to evidentiate those 3x3 boxes. The problem is when I try to get each button's ID it says 'undefined' and I can't do what I intended.
What am I doing wrong? Or how should I color those lines that I am talking about?
function createButtons() {
var gameboard = document.getElementById("gameboard");
for (var i = 1; i <= 9; i++) {
for (var j = 1; j <= 9; j++) {
var button = document.createElement("button");
button.id = i + "." + j;
button.innerHTML = "cell " + i + "-" + j;
gameboard.appendChild(button);
}
}
}
function drawLines() {
var button = document.getElementsByName("button");
for (var i = 1; i <= 81; i++) {
if (button.id == 3 + "." + i || button.id == 6 + "." + i) {
button.style.border.bottom = "5px solid red"; //I don't know if this is correct
}
if (button.id == i + "." + 3 || button.id == i + "." + 6) {
button.style.border = "5px";
button.style.border.right = "solid yellow";
}
}
}
createButtons();
drawLines();
body {
background-color: #0f4c5c;
}
h1,
h5 {
color: white;
}
.sudoku #gameboard {
width: 40vmin;
height: 40vmin;
display: grid;
grid-template-columns: repeat(9, 1fr);
gap: 0;
}
.sudoku button {
width: 10vmin;
height: 10vmin;
background: white;
margin: 0;
}
<body>
<div class="container">
<div class="col">
<h1 class="row mx-auto my-3" id="title">
Sudoku
</h1>
<div class="row my-2 container sudoku">
<div class="gameboard" id="gameboard"></div>
</div>
</div>
</div>
</div>
</body>
Your drawLines() function is the root of the problem here.
As stated in my commend, getElementsByName will return undefined in this instance as there is no element on the DOM with a name attribute.
A different approach you could take would be to give every button a class name and target them all using getElementsByClassName, which you can then loop through, possibly using a map or forEach.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
In order to get every third element in the array, consider using the modulus operator (%).
Please have a look at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Remainder for more information on usage of modulus.
Related
I want to add 10 points when blue box goes into brown box.
I tried to set score = 0 and points to add = 10 but it doesn't work.
I alert '+10 points' and it shows me the alert so I guess the problem is the DOM ?!?
Any suggestions ?
Thanks !
let moveCounter = 0;
let score = 0;
let obs = 10;
document.getElementById('score').textContent = '0';
var grid = document.getElementById("grid-box");
for (var i = 1; i <= 49; i++) {
var square = document.createElement("div");
square.className = 'square';
square.id = 'square' + i;
grid.appendChild(square);
}
var obstacles = [];
while (obstacles.length < 10) {
var randomIndex = parseInt(49 * Math.random());
if (obstacles.indexOf(randomIndex) === -1) {
obstacles.push(randomIndex);
var drawObstacle = document.getElementById('square' + randomIndex);
$(drawObstacle).addClass("ob")
}
}
var playerOne = [];
while (playerOne.length < 1) {
var randomIndex = parseInt(49 * Math.random());
if (playerOne.indexOf(randomIndex) === -1) {
playerOne.push(randomIndex);
var drawPone = document.getElementById('square' + randomIndex);
$(drawPone).addClass("p-0")
}
}
var addPoints = $('#score');
$('#button_right').on('click', function() {
if ($(".p-0").hasClass("ob")) {
alert('add +10 points !!!')
addPoints.text( parseInt(addPoints.text()) + obs );
}
moveCounter += 1;
if ($(".p-0").hasClass("ob")) {
}
$pOne = $('.p-0')
$pOneNext = $pOne.next();
$pOne.removeClass('p-0');
$pOneNext.addClass('p-0');
});
#grid-box {
width: 400px;
height: 400px;
margin: 0 auto;
font-size: 0;
position: relative;
}
#grid-box>div.square {
font-size: 1rem;
vertical-align: top;
display: inline-block;
width: 10%;
height: 10%;
box-sizing: border-box;
border: 1px solid #000;
}
.ob {
background-color: brown;
}
.p-0 {
background-color: blue;
}
<script src="https://code.jquery.com/jquery-1.12.4.js"></script>
<div id="grid-box">
</div>
<div class="move">
<button id="button_right">right</button><br>
</div>
<div id="score">
</div>
Thank you very much! I am new to JavaScript/ JQuery
Thank you very much!
You are trying to change the HTML inside of the div with id "score".
Selecting the css element using $("#id") retrieves the DOM element and not its contents so adding the score directly to it has no consequences.
What you want to do is: update the score variable and then set the HTML inside the div to the score value.
So instead of just:
addPoints += obs
you should
score += obs
addPoints.html(score)
Okay so this is a bit hard to explain this, but I am trying to make where whenever a number is "spawned" or generated, it fades in instead of just popping up.
Here is the Fiddle that I am trying to do that with. I am using a input tag for the number and a for statement to generate the rest--
for (I = 0; I < $("#input:text").val(); I++) {
N.innerHTML += 1 + I + " "
}
I hope I explained that well enough so people understand!
Append span elements instead of text so that you can easily select elements using selector.
Use setTimeout to make it happen serially using index.
Try this:
var D = document,
In = D.getElementById("input"),
CC = D.getElementById("submit"),
N = D.getElementById("N"),
I;
$(In).keyup(function(Key) {
if (Key.keyCode == 13) {
for (var i = 0; i < $("#input:text").val().length; i++) {
var span = '<span style=\'display:none\'>' + (i + 1) + ' ' + $("#input:text").val()[i] + ' </span>'; //set display of `span` element as `none`
N.innerHTML += span;
}
}
$('#N span').each(function(i) {
setTimeout(function() {
$(this).hide().fadeIn(500);
}.bind(this), (i * 500)); // `.bind()` will pass the outer `this` context in`setTimeout` when handler is invoked
})
});
$(CC).click(function() {
N.innerHTML = "";
});
body {
cursor: default;
outline-width: 0px;
}
#main {
text-align: center;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<body>
<div id="main">
<input type="text" id="input" maxlength="3" placeholder="Press submit to clear all" />
<input type="submit" id="submit" />
</div>
<h1 id="N"></h1>
</body>
Fiddle here
The jQuery fadeIn method would make this trivial. But if you want to do this with no libraries you can modify the opacity of the result div in a recursive loop. I modified your fiddle here and included it below. The key points are setting the result div to opacity:0 at start, then recursively calling the "fadeIn" function after your original code has ran. you can tweak the timeout delay and opacity increment to get the desired speed and smoothness of the fade effect.
HTML:
<body>
<div id="main">
<input type="text" id="input" maxlength="3" placeholder="Press submit to clear all" />
<input type="submit" id="clear" />
</div>
<h1 id="N"></h1>
</body>
CSS:
body {
cursor: default;
outline-width: 0px;
}
#main {
text-align: center;
}
#N {
opacity: 0;
}
JavaScript:
var D = document,
In = D.getElementById("input"),
CC = D.getElementById("clear"),
N = D.getElementById("N"),
I,
O = 0;
var fadeIn = function() {
O += 0.05
D.getElementById("N").style.opacity = O;
if (O < 1) {
setTimeout(fadeIn, 100)
}
}
$(In).keyup(function(Key) {
if (Key.keyCode == 13) {
for (I = 0; I < $("#input:text").val(); I++) {
N.innerHTML += 1 + I + " "
}
setTimeout(fadeIn, 100)
}
});
$(CC).click(function() {
N.innerHTML = "";
});
I'm working on a card game where the user has to select a card from a set of 4. If it is an Ace then they win if not then they lose. But I'm having some trouble removing the event listener of click from the set of cards after the first card has been clicked.
for(var i = 0; i < card.length; i++)
{
card[i].addEventListener("click",display);
}
function display()
{
this.setAttribute("src","CardImages/" + deck[this.id] + ".jpg");
this.setAttribute("class","highlight");
if(firstGo == 0)
{
firstGo++;
firstCard = this;
this.removeEventListener("click",display);
console.log("card" + deck[this.id]);
}
else
{
alert("You've already selected a card");
this.removeEventListener("click",display);
}
}
You are adding click events using a loop because you have multiple cards.
for(var i = 0; i < card.length; i++) {
card[i].addEventListener("click", display);
}
but you're removing the event listeners using
this.removeEventListener("click",display);
which will only remove the listener on the card you clicked. If you want to remove the listener on other cards too, you should also remove them in a loop.
function display() {
this.setAttribute("src","CardImages/" + deck[this.id] + ".jpg");
this.setAttribute("class","highlight");
if (firstGo == 0) {
firstGo++;
firstCard = this;
// this.removeEventListener("click",display);
for (var i = 0; i < card.length; i++) {
card[i].removeEventListener("click", display);
}
console.log("card" + deck[this.id]);
} else {
alert("You've already selected a card");
// this.removeEventListener("click",display);
for (var i = 0; i < card.length; i++) {
card[i].removeEventListener("click", display);
}
}
}
Here's a working demo.
var cards = document.getElementsByClassName("card");
for (var i = 0; i < cards.length; i++) {
cards[i].addEventListener("click", display);
}
function display() {
this.classList.add("highlight");
for (var i = 0; i < cards.length; i++) {
cards[i].removeEventListener("click", display);
}
}
.card {
float: left;
padding: 50px 40px;
border: 1px solid rgba(0,0,0,.2);
margin: 5px;
background: white;
}
.card:hover {
border: 1px solid rgba(0,0,255,.4);
}
.card.highlight {
border: 1px solid rgba(0,200,0,.5);
}
<div class="card">1</div>
<div class="card">2</div>
<div class="card">3</div>
<div class="card">4</div>
I'm not sure what your card array looks like, but I filled in the rest on a codepen and it seems to be successfully removing the eventListener. Is your card array referencing specific DOM elements like this for example?
var a = document.getElementById('A');
var b = document.getElementById('B');
var c = document.getElementById('C');
var card = [a, b, c];
I've made a JavaScript dropdown menu. Everything works fine, except the background image. I have the image set to change when the dropdown menu is expanded, which also works fine.
The issue is with the headers. Unless the header is set to display inline-block or inline, the menu won't expand. When set to inline-block or inline everything expands when you click on the box. But if you click on the header itself, it adds the padding and border around the header and ads in the background image from the div. How do you prevent this from happening?
<div class="panel">
<div class="collapse"><h2>Features</h2></div>
<div class="elements">
text<br>text<br>text
</div>
</div>
<style>
h2 {/*display: inline-block;*/
/*display: inline;*/
margin: 0px;
padding: 0px 0px 0px 0px;
color: #ffffff;
text-align: center;
text-transform: uppercase;}
.expand,
.collapse {cursor: pointer;
background-position: center right;
background-repeat: no-repeat;
background-color: #000033;
border: 2px solid #990044;
color: #ffffff;
padding: 10px 0px;
text-align: center;}
.collapse {background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAcCAYAAAByDd+UAAABHUlEQVRIS+3USw6CMBAA0BYNutOjcAQ9iXHjhoXhBt4AEmwwbvQm6g04ii4hCLaNNRUp/dDgQllRPvMy05lC0PMFe/bAH7Re8R8qaYySTZGPoyBYXm3WMQwP04Gbhfd8FJDYtKTxNjkCCBf4Ni3y0dwWSrChm51wXI/FhjHaRXix5rKygtYwGr4C1QUitPdKUJ7xemILbcJw7JsDnBktqU20DfP9VfoaCxuoDCPJvc1hF1QF+wBNy6uKNYK6qA4mBFVRXawVlKHkPTfUbKJo65NuFJ1W0sNb1EjPgOQEUcakGbJIApRPQpoZ+1iaoQKqjCln2IJqYdpgrZGArEGaGke5pPzPZE/Juq0bjbtU9KPpc6MMTTGjPeyCfQV8AK4c2lwJRjQ3AAAAAElFTkSuQmCC);}
.expand {background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAcCAYAAAByDd+UAAABD0lEQVRIS+3Wyw2CQBAG4F1Q8KadSAnYgR0YL164SCWYKDHxonZgB1ICdiI3QR6yCgSVXXaAkGDkwgXyZf6dYcCo5Qu37KFugIaxH5FkdH1+hSYErpBgPck9E8j35AkUBYE5TEkqs6EoN1iApWmCUC6QgYHRUpCCOYk0zDUNV6VMkIYJSFAJFKLQim8glAqyME1b2AQ0zZ0CRQtBHiyNEop+gRCsCvoGVsGgaAbWwSDoE2wC40VxkxgPiteb7QFhPMsNsEPmLG196DZgolF0fFXYd614M47jhxvBCtEIXfy7rGZnKEq3k4jEZd3KPhMhcxqgYBV4gylZZaXf0qqR0t77g00n2pG/tjpl/37TPACe/d8VUJ3+EgAAAABJRU5ErkJggg==);}
.elements {background-color: #ccd9ff;
overflow: hidden;}
</style>
<script>
function aaManageEvent (eventObj, event, eventHandler) {
if (eventObj.addEventListener) {eventObj.addEventListener (event, eventHandler, false);}
else if (eventObj.attachEvent) {event = "on" + event; eventObj.attachEvent (event, eventHandler);}
}
window.onload = function () {
var divs = document.getElementsByTagName ("div");
for (var i = 0; i < divs.length; i++) {
if (divs[i].className == "collapse") {
aaManageEvent (divs [i], "click", spring.expandOrCollapse);
}
else if (divs[i].className == "elements") {
var height = divs [i].offsetHeight;
divs [i] .height = height;
if (divs [i] .id == "") divs [i].id = "div" + i;
divs [i].style.height = "0";
}
}
}
var spring = {
// adjust height
adjustItem : function (val, newItem) {
document.getElementById (newItem).style.height = val + "px";
},
// check if expand or collapse
expandOrCollapse : function (evnt) {
evnt = evnt ? evnt : window.event;
var target = evnt.target ? evnt.target : evnt.srcElement;
if (target.className == "collapse") spring.expand (target);
else spring.collapse (target);
},
// Expand Panel
expand : function (target) {
target.className = 'expand';
var children = target.parentNode.childNodes, panel;
for (var i = 0; i < children.length; i++) {
if (children [i].className == "elements") {
panel = children [i]; break;
}
}
var height = panel.height, incr = height / 20;
for (var i=0; i < 20; i++) {
var val = (i + 1) * incr;
var func = "spring.adjustItem (" + val + ", '" + panel.id + "')";
setTimeout (func, (i + 1) * 30);
}
},
// Collapse Panel
collapse : function (target) {
target.className = "collapse";
var children = target.parentNode.childNodes, panel;
for (var i = 0; i < children.length; i++) {
if (children [i].className == "elements") {
panel = children [i]; break;
}
}
var height = panel.height, decr = height / 20;
for (var i = 0; i < 20; i++) {
var val = height - (decr * (i + 1));;
var func = "spring.adjustItem (" + val + ", '" + panel.id + "')";
setTimeout (func, (i + 1) * 30);
}
}
};
</script>
When I click on the div, the dropdown works. But when I click on the header, I see an error in the browser console.
I think because when clicking on the <h2>Features</h2> element, the click event bubbles up to the <div class="collapse">, making the var target in this line not the <div class="collapse"> but the <h2>:
var target = evnt.target ? evnt.target : evnt.srcElement;
A possible solution to fix this is for example to add an id to this line:
<div id="header" class="collapse"><h2>Features</h2></div>
Then you can directly get that div by id and change the classname.
I've adjusted your expandOrCollapse function to make it toggle based on the classname from the div with id="header".
For example:
function aaManageEvent (eventObj, event, eventHandler) {
if (eventObj.addEventListener) {eventObj.addEventListener (event, eventHandler, false);}
else if (eventObj.attachEvent) {event = "on" + event; eventObj.attachEvent (event, eventHandler);}
}
window.onload = function () {
var divs = document.getElementsByTagName ("div");
for (var i = 0; i < divs.length; i++) {
if (divs[i].className == "collapse") {
aaManageEvent (divs [i], "click", spring.expandOrCollapse);
}
else if (divs[i].className == "elements") {
var height = divs [i].offsetHeight;
divs [i] .height = height;
if (divs [i] .id == "") divs [i].id = "div" + i;
divs [i].style.height = "0";
}
}
}
var spring = {
// adjust height
adjustItem : function (val, newItem) {
document.getElementById (newItem).style.height = val + "px";
},
// check if expand or collapse
expandOrCollapse : function (evnt) {
var header = document.getElementById('header');
if (header.className === "collapse") {
spring.expand(header);
} else {
spring.collapse(header);
}
},
// Expand Panel
expand : function (target) {
target.className = 'expand';
var children = target.parentNode.childNodes, panel;
for (var i = 0; i < children.length; i++) {
if (children [i].className == "elements") {
panel = children [i]; break;
}
}
var height = panel.height, incr = height / 20;
for (var i=0; i < 20; i++) {
var val = (i + 1) * incr;
var func = "spring.adjustItem (" + val + ", '" + panel.id + "')";
setTimeout (func, (i + 1) * 30);
}
},
// Collapse Panel
collapse : function (target) {
target.className = "collapse";
var children = target.parentNode.childNodes, panel;
for (var i = 0; i < children.length; i++) {
if (children [i].className == "elements") {
panel = children [i]; break;
}
}
var height = panel.height, decr = height / 20;
for (var i = 0; i < 20; i++) {
var val = height - (decr * (i + 1));;
var func = "spring.adjustItem (" + val + ", '" + panel.id + "')";
setTimeout (func, (i + 1) * 30);
}
}
};
h2 {/*display: inline-block;*/
/*display: inline;*/
margin: 0px;
padding: 0px 0px 0px 0px;
color: #ffffff;
text-align: center;
text-transform: uppercase;}
.expand,
.collapse {cursor: pointer;
background-position: center right;
background-repeat: no-repeat;
background-color: #000033;
border: 2px solid #990044;
color: #ffffff;
padding: 10px 0px;
text-align: center;}
.collapse {background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAcCAYAAAByDd+UAAABHUlEQVRIS+3USw6CMBAA0BYNutOjcAQ9iXHjhoXhBt4AEmwwbvQm6g04ii4hCLaNNRUp/dDgQllRPvMy05lC0PMFe/bAH7Re8R8qaYySTZGPoyBYXm3WMQwP04Gbhfd8FJDYtKTxNjkCCBf4Ni3y0dwWSrChm51wXI/FhjHaRXix5rKygtYwGr4C1QUitPdKUJ7xemILbcJw7JsDnBktqU20DfP9VfoaCxuoDCPJvc1hF1QF+wBNy6uKNYK6qA4mBFVRXawVlKHkPTfUbKJo65NuFJ1W0sNb1EjPgOQEUcakGbJIApRPQpoZ+1iaoQKqjCln2IJqYdpgrZGArEGaGke5pPzPZE/Juq0bjbtU9KPpc6MMTTGjPeyCfQV8AK4c2lwJRjQ3AAAAAElFTkSuQmCC);}
.expand {background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAcCAYAAAByDd+UAAABD0lEQVRIS+3Wyw2CQBAG4F1Q8KadSAnYgR0YL164SCWYKDHxonZgB1ICdiI3QR6yCgSVXXaAkGDkwgXyZf6dYcCo5Qu37KFugIaxH5FkdH1+hSYErpBgPck9E8j35AkUBYE5TEkqs6EoN1iApWmCUC6QgYHRUpCCOYk0zDUNV6VMkIYJSFAJFKLQim8glAqyME1b2AQ0zZ0CRQtBHiyNEop+gRCsCvoGVsGgaAbWwSDoE2wC40VxkxgPiteb7QFhPMsNsEPmLG196DZgolF0fFXYd614M47jhxvBCtEIXfy7rGZnKEq3k4jEZd3KPhMhcxqgYBV4gylZZaXf0qqR0t77g00n2pG/tjpl/37TPACe/d8VUJ3+EgAAAABJRU5ErkJggg==);}
.elements {background-color: #ccd9ff;
overflow: hidden;}
<div class="panel">
<div id="header" class="collapse"><h2>Features</h2></div>
<div class="elements">
text<br>text<br>text
</div>
</div>
Edit your declaration block of h2 as shown below. This will solve your problem.
h2 {
display: inline-block;
margin: 0px;
padding: 0px 0px 0px 0px;
color: #ffffff;
text-align: center;
text-transform: uppercase;
pointer-events: none; // this line solves your problem.
}
CSS property pointer-events let you control under what circumstances an element can become the target of mouse events. when you set it to none, the element will never be the target of mouse events. So, the click event passed on to its descendant elements (here the box).
I am trying to make a chessboard using javascript and creating 64 divs with it.
The problem is, that it creates only the first div.
Here is the code:
div {
width: 50px;
height: 50px;
display: block;
position: relative;
float: left;
}
<script type="text/javascript">
window.onload=function()
{
var i=0;
var j=0;
var d=document.createElement("div");
for (i=1; i<=8; i++)
{
for (j=1; j<=8; j++)
{
if ((i%2!=0 && j%2==0)||(i%2==0 && j%2!=0))
{
document.body.appendChild(d);
d.className="black";
}
else
{
document.body.appendChild(d);
d.className="white";
}
}
}
}
</script>
As t-j-crowder has noted, the OP's code only creates one div. But, for googlers, there is one way to append multiple elements with a single appendChild in the DOM: by creating a documentFragment.
function createDiv(text) {
var div = document.createElement("div");
div.appendChild(document.createTextNode(text));
return div;
}
var divs = [
createDiv("foo"),
createDiv("bar"),
createDiv("baz")
];
var docFrag = document.createDocumentFragment();
for(var i = 0; i < divs.length; i++) {
docFrag.appendChild(divs[i]); // Note that this does NOT go to the DOM
}
document.body.appendChild(docFrag); // Appends all divs at once
The problem is, that it creates only the first div.
Right, because you've only created one div. If you want to create more than one, you must call createElement more than once. Move your
d=document.createElement("div");
line into the j loop.
If you call appendChild passing in an element that's already in the DOM, it's moved, not copied.
window.onload=function()
{
var i=0;
var j=0;
for (i=1; i<=8; i++)
{
for (j=1; j<=8; j++)
{
if ((i%2!=0 && j%2==0)||(i%2==0 && j%2!=0))
{
var d=document.createElement("div");
document.body.appendChild(d);
d.className="black";
}
else
{
var d=document.createElement("div");
document.body.appendChild(d);
d.className="white";
}
}
}
}
Although what T.J. Crowder writes works fine, I would recommend rewriting it to the code below, using a documentFragment, like Renato Zannon suggested. That way you will only write to the DOM once.
window.onload = function() {
var count = 5,
div,
board = document.getElementById('board'),
fragment = document.createDocumentFragment();
// rows
for (var i = 0; i < count; ++i) {
// columns
for (var j = 0; j < count; ++j) {
div = document.createElement('div');
div.className = (i % 2 != 0 && j % 2 == 0) || (i % 2 == 0 && j % 2 != 0) ? 'black' : 'white';
fragment.appendChild(div);
}
}
board.appendChild(fragment);
};
#board {
background-color: #ccc;
height: 510px;
padding: 1px;
width: 510px;
}
.black,
.white {
float: left;
height: 100px;
margin: 1px;
width: 100px;
}
.black {
background-color: #333;
}
.white {
background-color: #efefef;
}
<div id="board"></div>
function crt_dv(){
dv=document.createElement('div'),document.body.appendChild(dv)
};
crt_dv(),dv.className='white';crt_dv(),dv.className='black';
Also use: for(i=0;i<2;i++)