Here is an example of a JavaScript game add to 15. You will play with the computer and first to have a set of 3 adding to 15 wins.
JavaScript Game - Add to 15
<html>
<head>
<title>
Add to 15
</title>
<meta charset="UTF-8">
<style>
span {
position:absolute;
top:180px;
border-style: solid;
color: red;
border-radius: 25px;
background-color: yellow;
padding: 5px;
cursor: pointer;
}
#status {
color: red;
font-size: x-large;
}
</style>
<script language="Javascript">
var statusref;
var numbers = [];
var game = true;
var player = [];
var computer = [];
var board = [1,2,3,4,5,6,7,8,9];
var wedge = 50;
var startx = 15;
var groups = [
" ",
"3 4 8",
"1 5 9",
"2 6 7",
"1 6 8",
"3 5 7",
"2 4 9",
"2 5 8",
"4 5 6"
];
var occupied = [
[2, 4],
[3, 6, 7],
[1, 5],
[1, 6, 8],
[2, 5, 7, 8],
[3, 4, 8],
[3, 5],
[1, 4, 7],
[2, 6]
];
var pgroupcount = [0,0,0,0,0,0,0,0,0];
var cgroupcount = [0,0,0,0,0,0,0,0,0];
function init() {
setUpBoard();
statusref=document.getElementById("status");
}
function smartChoice() {
var boardl = board.length;
for (var i=0;i<boardl;i++) {
var possible = board[i];
for (var j=0;j<occupied[possible-1].length;j++) {
if (cgroupcount[occupied[possible-1][j]]==2) {
return (i);
}
}
}
for (var i=0;i<boardl;i++) {
var blocker = board[i];
for (var j=0;j<occupied[blocker-1].length;j++) {
if (pgroupcount[occupied[blocker-1][j]]==2) {
return(i);
}
}
}
for (var i=0;i<boardl;i++) {
var possible = board[i];
for (var j=0;j<occupied[possible-1].length;j++) {
var whatgroup = occupied[possible-1][j];
if ((cgroupcount[whatgroup]==1)&&(pgroupcount[whatgroup]==0 )){
return (i);
}
}
}
for (var i = 0;i<boardl;i++) {
if (board[i]==5) {
return (i);
}
}
for (var i = 0;i<boardl;i++) {
if (0==board[i]%2) {
return (i);
}
}
var ch = Math.floor(Math.random(0,boardl));
return (ch);
}
function computerMove() {
if (board.length<1) {
statusref.innerHTML="Cat wins!";
return;
}
var which = smartChoice();
var n = board[which];
take(n);
numbers[n-1].style.top = "150px";
numbers[n-1].removeEventListener("click",addToPlayer);
computer.push(n);
var holder = occupied[n-1];
for (var i=0;i<holder.length;i++) {
cgroupcount[holder[i]]++;
if (cgroupcount[holder[i]]==3) {
statusref.innerHTML ="Computer wins "+groups[holder[i]];
game = false;
return;
}
}
if (board.length<1) {
statusref.innerHTML="Cat wins!";
}
else {
game = true;
}
}
function setUpBoard() {
var dv;
var xpos;
for (var i=1; i<10; i++) {
dv = document.createElement("span");
dv.addEventListener("click",addToPlayer);
dv.innerHTML = i.toString();
xpos = startx + i*wedge;
dv.style.left=xpos.toString()+"px";
dv.style.top ="240px";
document.body.appendChild(dv);
dv.n = i;
numbers.push(dv);
}
}
function take(n) {
var nAt = board.indexOf(n);
if (nAt>-1) {
board.splice(nAt,1);
}
}
function addToPlayer(ev) {
if (game) {
var nn = ev.target.n;
ev.target.removeEventListener("click",addToPlayer);
player.push(nn);
numbers[nn-1].style.top = "350px";
take(nn);
var holder = occupied[nn-1];
for (i=0;i<holder.length;i++) {
pgroupcount[holder[i]]++;
if (pgroupcount[holder[i]]==3) {
statusref.innerHTML="Player wins "+groups[holder[i]];
game = false;
return ;
}
}
game = false;
setTimeout(computerMove,1000);
}
else {
statusref.innerHTML="Reload for new game.";
}
}
</script>
<body onLoad="init();">
<h1>
Player against Computer
</h1>
<br>
Player goes first: click on number. First to have a set of 3 adding to 15 wins. Reload for new game.
<p>
Computer
<br>
<br>
<br>
</p>
<hr/>
Board
<br>
<br>
<br>
<br>
<hr/>
Player
<br>
<br>
<br>
<br>
<br>
<hr/>
<div id="status">
</div>
</body>
</html>
Output
As shown in the featured image of this article.