Adding Start, Stop, Reset button for timer - javascript

I have this count-up timer code and want to add start, stop and reset button. It start right at the page load.
<script type="text/javascript">
var timerVar = setInterval(countTimer, 1000);
var totalSeconds = 0;
function countTimer() {
++totalSeconds;
var hour = Math.floor(totalSeconds /3600);
var minute = Math.floor((totalSeconds - hour*3600)/60);
var seconds = totalSeconds - (hour*3600 + minute*60);
document.getElementById("hour").innerHTML =hour;
document.getElementById("minute").innerHTML =minute;
document.getElementById("seconds").innerHTML =seconds;
}
</script>

It's just some simple manipulation of hour, minute and seconds and making use of clearInterval and setInterval. In my snipper, reset won't stop the timer, but it's easy to make that happen by a few lines of code.
window.onload = () => {
let hour = 0;
let minute = 0;
let seconds = 0;
let totalSeconds = 0;
let intervalId = null;
function startTimer() {
++totalSeconds;
hour = Math.floor(totalSeconds /3600);
minute = Math.floor((totalSeconds - hour*3600)/60);
seconds = totalSeconds - (hour*3600 + minute*60);
document.getElementById("hour").innerHTML =hour;
document.getElementById("minute").innerHTML =minute;
document.getElementById("seconds").innerHTML =seconds;
}
document.getElementById('start-btn').addEventListener('click', () => {
intervalId = setInterval(startTimer, 1000);
})
document.getElementById('stop-btn').addEventListener('click', () => {
if (intervalId)
clearInterval(intervalId);
});
document.getElementById('reset-btn').addEventListener('click', () => {
totalSeconds = 0;
document.getElementById("hour").innerHTML = '0';
document.getElementById("minute").innerHTML = '0';
document.getElementById("seconds").innerHTML = '0';
});
}
<div>Hour: <span id="hour"></span></div>
<div>Minute: <span id="minute"></span></div>
<div>Second: <span id="seconds"></span></div>
<button id="start-btn">Start</button>
<button id="stop-btn">Stop</button>
<button id="reset-btn">Reset</button>

Duplicate of Adding start, stop, and reset buttons for a timer
but just because there is not the HTML part, there is the full answer (html + js thanks to #closure )
(function() {
"use strict";
var secondsLabel = document.getElementById('seconds'),
minutesLabel = document.getElementById('minutes'),
hoursLabel = document.getElementById('hours'), totalSeconds = 0,
startButton = document.getElementById('start'),
stopButton = document.getElementById('stop'),
resetButton = document.getElementById('reset'), timer = null;
startButton.onclick = function() {
if (!timer) {
timer = setInterval(setTime, 1000);
}
};
stopButton.onclick = function() {
if (timer) {
clearInterval(timer);
timer = null;
}
};
resetButton.onclick = function() {
if (timer) {
totalSeconds = 0;
stop();
}
};
function setTime() {
totalSeconds++;
secondsLabel.innerHTML = pad(totalSeconds % 60);
minutesLabel.innerHTML = pad(parseInt(totalSeconds / 60));
hoursLabel.innerHTML = pad(parseInt(totalSeconds / 3600))
}
function pad(val) {
var valString = val + "";
if (valString.length < 2) {
return "0" + valString;
} else {
return valString;
}
}
})();
<p id='seconds'></p>
<p id='minutes'></p>
<p id='hours'></p>
<button id='start'>start</button>
<button id='stop'>stop</button>
<button id='reset'>reset</button>

//DOM CACHE
const startBtn = document.querySelector("#start-btn")
const stopBtn = document.querySelector("#stop-btn")
const resetBtn = document.querySelector("#reset-btn")
var minDigits = document.getElementById("min");
var secDigits = document.getElementById("sec");
//INITIALIZING VARIABLES
var hrs = 0;
var mins = 0;
var secs = 0;
var countSec = 0;
var timerVar = null;
//FUNCTIONS=============
function startCounter() {
++countSec;
hrs = Math.floor(countSec /3600);
mins = Math.floor((countSec - hrs*3600)/60);
secs = countSec - (hrs*3600 + mins*60);
if (secs < 10) {
secDigits.innerHTML = "0" + secs;
} else { secDigits.innerHTML = secs; }
minDigits.innerHTML = "0" + mins;
}
startBtn.addEventListener('click', () => {
timerVar = setInterval(startCounter, 1000);
})
stopBtn.addEventListener('click', () => {
if (timerVar)
clearInterval(timerVar);
});
resetBtn.addEventListener('click', () => {
countSec = 0;
secDigits.innerHTML = "00";
minDigits.innerHTML = "00";
clearInterval(timerVar);
});
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" href="style.css">
<title>Clock JS</title>
</head>
<body>
<div class="container">
<header>
<h1>SIMPLE COUNTER</h1>
<p>At A Time No Time To Check Time</p>
</header>
<div class="clock-face">
<div class="digital-time"></div>
<div class="greeting"></div>
<div class="screen">
<h1 class="digits">
<span id="min" class="minutes">00</span>:<span id="sec" class="seconds">00</span>
</h1>
</div>
<div class="clock-dial">
<button id="start-btn">start</button>
<button id="stop-btn">stop</button>
<button id="reset-btn">reset</button>
</div>
</div>
</div>
<script src="app.js" charset="utf-8"></script>
</body>
</html>

Related

How to toggle a button with Javascript

I want to create a phone-like stopwatch using HTML, CSS, and vanilla JavaScript. The one I have already done does the task, but I don't want a separate button for stopping and starting. How could I make a button that changes from start to stop and stop to start?
Here is my HTML Code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div class="wrapper">
<h1>Stopwatch</h1>
<h2>Vanilla JavaScript Stopwatch</h2>
<p><span id="seconds">00</span>:<span id="tens">00</span></p>
<button id="button-start">Start</button>
<button id="button-stop">Stop</button>
<button id="button-reset">Reset</button>
</div>
</body>
</html>
Here is my JavaScript code:
window.onload = function () {
var seconds = 00;
var tens = 00;
var appendTens = document.getElementById("tens")
var appendSeconds = document.getElementById("seconds")
var buttonStart = document.getElementById('button-start');
var buttonStop = document.getElementById('button-stop');
var buttonReset = document.getElementById('button-reset');
var Interval ;
buttonStart.onclick = function() {
clearInterval(Interval);
Interval = setInterval(startTimer, 10);
}
buttonStop.onclick = function() {
clearInterval(Interval);
}
buttonReset.onclick = function() {
clearInterval(Interval);
tens = "00";
seconds = "00";
appendTens.innerHTML = tens;
appendSeconds.innerHTML = seconds;
}
function startTimer () {
tens++;
if(tens <= 9){
appendTens.innerHTML = "0" + tens;
}
if (tens > 9){
appendTens.innerHTML = tens;
}
if (tens > 99) {
console.log("seconds");
seconds++;
appendSeconds.innerHTML = "0" + seconds;
tens = 0;
appendTens.innerHTML = "0" + 0;
}
if (seconds > 9){
appendSeconds.innerHTML = seconds;
}
}
}
Define a boolean to track if the clock is running or not and combine the start and stop function into one: something like this:
var clockStarted = false;
buttonStart.onclick = function() {
clearInterval(Interval);
if (!clockStarted) {
Interval = setInterval(startTimer, 10);
clockStarted = true;
} else {
clockStarted = false;
}
}
buttonReset.onclick = function() {
clearInterval(Interval);
tens = "00";
seconds = "00";
appendTens.innerHTML = tens;
appendSeconds.innerHTML = seconds;
clockStarted = false;
}
You could make your play-button invisible after clicking on it (buttonStart.style.dispaly = "none") and enable your stop-button (buttonStop.style.dispaly = "block") and do the same in reverse in your stop function.
Another possible way would be to use only one button and save the state of your player in a variable (i.e. a boolen isPlaying). Then you'd only need one onPress method which starts or stops the player according to isPlaying. Youd also need to change the element or the icon on you button accoring to this variable.

Transforming minutes to ms giving unexpected result

Im developing a chess clock. The thing is that when Im retrieving the minutes and seconds from the DOM and transforming it with msToClockFormat I'm getting 100 times extra minutes. However, For more I look at the function, the more convinced I am that is working as it should be. The minutes are being divided by 60000, 1000 times 60`, and I dont see the error. Thanks.
let btn1 = document.getElementById("btn1");
let btn2 = document.getElementById("btn2");
let resetBtn = document.getElementById("reset");
let ms1 = stringTimeToMs(btn1.innerHTML);
let ms2 = stringTimeToMs(btn2.innerHTML);
let player1 = true;
let reset = false;
function tick() {
if (!reset) {
if (player1) {
btn1.innerHTML = msToClockFormat(--ms1);
} else {
btn2.innerHTML = msToClockFormat(--ms2);
}
}
}
function msToClockFormat(ms) {
let minutes = Math.floor(ms / 60000);
let seconds = Math.floor((ms % 60000) / 1000);
return minutes + ":" + (seconds < 10 ? "0" + seconds : seconds);
}
function stringTimeToMs(time) {
let minutes = time.split(":")[0];
let seconds = time.split(":")[1];
return (minutes * 60 + seconds) * 1000;
}
var myInterval = setInterval(tick, 1);
btn1.addEventListener("click", () => {
player1 = false;
reset = false;
})
btn2.addEventListener("click", () => {
player1 = true;
reset = false;
})
resetBtn.addEventListener("click", () => {
btn1.innerHTML = "05:00";
btn2.innerHTML = "05:00";
player1 = true;
ms1 = 5 * 60 * 1000;
ms2 = 5 * 60 * 1000;
reset = true;
})
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Clock</title>
<link rel="stylesheet" href="https://unpkg.com/#picocss/pico#latest/css/pico.min.css">
<script src="script.js" defer></script>
</head>
<body>
<main class="container">
<div class="container1">
<button class="timers" id="btn1">3:00</button>
</div>
<div class="container2">
<button class="timers" id="btn2">3:00</button>
</div>
<div class="container3">
<button id="reset">RESET</button>
</div>
</main>
</body>
</html>
You'd probably have a better time keeping your state in your code, and just writing it into the DOM elements.
I changed the tick interval to 1000ms (because it's unlikely setInterval would work correctly with 1ms), but even so it's not guaranteed that your function will be called exactly 1000ms apart, so it would be better to look at the wall clock (+new Date()) to see how much time actually elapsed since the last "tick".
let btn1 = document.getElementById("btn1");
let btn2 = document.getElementById("btn2");
let resetBtn = document.getElementById("reset");
let ms1 = 300000;
let ms2 = 300000;
let player1 = true;
let reset = false;
function update() {
btn1.innerHTML = msToClockFormat(ms1);
btn2.innerHTML = msToClockFormat(ms2);
}
function tick() {
if (!reset) {
if (player1) {
ms1 -= 1000;
} else {
ms2 -= 1000;
}
}
update();
}
function msToClockFormat(ms) {
let minutes = Math.floor(ms / 60000);
let seconds = Math.floor((ms % 60000) / 1000);
return minutes + ":" + (seconds < 10 ? "0" + seconds : seconds);
}
update();
var myInterval = setInterval(tick, 1000);
btn1.addEventListener("click", () => {
player1 = false;
reset = false;
})
btn2.addEventListener("click", () => {
player1 = true;
reset = false;
})
resetBtn.addEventListener("click", () => {
player1 = true;
ms1 = 5 * 60 * 1000;
ms2 = 5 * 60 * 1000;
reset = true;
})
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Clock</title>
<link rel="stylesheet" href="https://unpkg.com/#picocss/pico#latest/css/pico.min.css">
<script src="script.js" defer></script>
</head>
<body>
<main class="container">
<div class="container1">
<button class="timers" id="btn1"></button>
</div>
<div class="container2">
<button class="timers" id="btn2"></button>
</div>
<div class="container3">
<button id="reset">RESET</button>
</div>
</main>
</body>
</html>
Inside StringTimeToMs, seconds is being read as String input "00" as opposed to integer. As a result, adding seconds in return (minutes * 60 + seconds) * 1000; is concatenating "00" to the end of the number, making the number larger. Use parseInt to read the integer value.
function stringTimeToMs(time) {
let minutes = time.split(":")[0];
let seconds = parseInt(time.split(":")[1]);
return (minutes * 60 + seconds) * 1000;
}

Javascript cannot display countdown timer which also starts on button click

I am creating a countdown timer and I managed to get the timer to display and countdown, but it starts automatically when the page loads. I would like to prevent this. I know how to add an event handler I just can't work out how to stop it loading automatically.
Edited as I forgot to copy in a a div with countdown as #id.
((d) => {
let start = d.getElementById("start");
let stop = d.getElementById("stop");
let reset = d.getElementById("reset");
let timerFormat = (s) => {
return (s - (s %= 60)) / 60 + (9 < s ? ":" : ":0") + s;
};
let counter;
let startTime = 1500;
timer = () => {
startTime--;
document.getElementById("countdown").innerHTML = timerFormat(startTime);
if (startTime === 0) clearInterval(counter);
};
counter = setInterval(timer, 1000);
startHandler = () => {
let el = document.getElementById("start");
el.addEventListener("click", counter);
};
})(document);
<div id="countdown"></div>
<button class="btn" id="start">Start</button>
<button class="btn" id="stop">Stop</button>
<button class="btn" id="reset">Reset</button>
You simply have to adde event handlers to the buttons like so:
start.onclick = ()=>{
counter = setInterval(timer, 1000);
}
stop.onclick = () => {
clearInterval(counter);
counter = undefined;
}
reset.onclick = ()=>{
startTime = 1500;
document.getElementById("countdown").innerHTML = timerFormat(startTime);
}
live demo:
((d) => {
let start = d.getElementById("start");
let stop = d.getElementById("stop");
let reset = d.getElementById("reset");
let timerFormat = (s) => {
return (s - (s %= 60)) / 60 + (9 < s ? ":" : ":0") + s;
};
let counter;
let startTime = 1500;
timer = () => {
startTime--;
document.getElementById("countdown").innerHTML = timerFormat(startTime);
if (startTime === 0) clearInterval(counter);
};
start.onclick = ()=>{
counter = counter || setInterval(timer, 1000);
}
stop.onclick = () => {
clearInterval(counter);
counter = undefined;
}
reset.onclick = ()=>{
startTime = 1500;
document.getElementById("countdown").innerHTML = timerFormat(startTime);
}
})(document);
<div id="countdown"></div>
<button class="btn" id="start">Start</button>
<button class="btn" id="stop">Stop</button>
<button class="btn" id="reset">Reset</button>

javascript bug using setTimeout()

I have this program which tells you your reaction time, and it works fine, but if you run the program and click the start button twice, instead of once, the background turns red right away, instead of waiting for the set interval. Thanks in advance to anyone that can help.
<!DOCTYPE html>
<html>
<head>
<script>
var button = document.getElementById("reactionTester");
var start = document.getElementById("start");
var startTime;
var scoreContainer = document.getElementById("p");
var css = document.createElement("style");
css.type = "text/css";
var counter = 0;
function init() {
var startInterval /*in milliseconds*/ = Math.floor(Math.random() * 10) * 1000;
setTimeout(startTimer, startInterval);
}
function startTimer() {
startTime = Date.now();
document.body.appendChild(css);
css.innerHTML = "html{background-color: red;}";
if (counter = 1) {
p1 = document.getElementsByTagName('p')[0];
p1.parentNode.removeChild(p1);
}
}
function stopTimer() {
if (startTime) {
var stopTime = Date.now();
var dif = stopTime - startTime;
alert("Your time is " + dif + " ms");
startTime = null;
css.innerHTML = null;
var p = document.createElement("p");
document.body.appendChild(p);
p.innerHTML = dif;
counter = 0;
counter++;
} else {
alert("don't trick me");
}
}
</script>
</head>
<body>
<form id="form">
<div class="tableRow">
<input type="button" value="start" id="start" onclick="init()">
</div>
<div class="tableRow">
<input type="button" id="reactionTester" onclick="stopTimer()" value="stop">
</div>
<div id="p">
</div>
</form>
</body>
</html>
There are 2 (potential) problems here:
Every time init() is run it resets startTime to Date.now(). So when stopTimer runs, it runs only against the latest click time.
init can set an interval of 0ms which may be intended...
To fix the first problem you can do one of a few things, but the most straightforward is to cancel the first timeout by getting a reference then later clearing it:
var timeoutId;
function init(){
if (timeout) clearTimeout(timeoutId);
timeoutId = setTimeout(func, delay);
}
You need to keep track of the timers in a variable so you can reset it.
<!DOCTYPE html>
<html>
<head>
<script>
var button = document.getElementById("reactionTester");
var start = document.getElementById("start");
var startTime;
var scoreContainer = document.getElementById("p");
var css = document.createElement("style");
css.type = "text/css";
var counter = 0;
var timer = null;
function init() {
var startInterval /*in milliseconds*/ = Math.floor(Math.random() * 10) * 1000;
clearTimeout(timer);
timer = setTimeout(startTimer, startInterval);
}
function startTimer() {
startTime = Date.now();
document.body.appendChild(css);
css.innerHTML = "html{background-color: red;}";
if (counter = 1) {
p1 = document.getElementsByTagName('p')[0];
p1.parentNode.removeChild(p1);
}
}
function stopTimer() {
if (startTime) {
var stopTime = Date.now();
var dif = stopTime - startTime;
alert("Your time is " + dif + " ms");
startTime = null;
css.innerHTML = null;
var p = document.createElement("p");
document.body.appendChild(p);
p.innerHTML = dif;
counter = 0;
counter++;
} else {
alert("don't trick me");
}
}
</script>
</head>
<body>
<form id="form">
<div class="tableRow">
<input type="button" value="start" id="start" onclick="init()">
</div>
<div class="tableRow">
<input type="button" id="reactionTester" onclick="stopTimer()" value="stop">
</div>
<div id="p">
</div>
</form>
</body>
</html>

Adding start, stop, and reset buttons for a timer

I'm making a timer and have it working already one load. I want to add a start, stop, and reset button to it. This is my code as is atm.
(function() {
"use strict";
var secondsLabel = document.getElementById('seconds'),
minutesLabel = document.getElementById('minutes'),
hoursLabel = document.getElementById('hours'),
totalSeconds = 0,
startButton = document.getElementById('start'),
resetButton = document.getElementById('reset'),
onOff = 0;
startButton.onclick = function() {
onOff = 1;
};
resetButton.onclick = function() {
totalSeconds = 0;
onOff = 0;
};
if ( onOff == 1 ) {
setInterval( setTime, 1000 );
function setTime() {
totalSeconds++;
secondsLabel.innerHTML = pad( totalSeconds % 60 );
minutesLabel.innerHTML = pad( parseInt( totalSeconds / 60 ) );
hoursLabel.innerHTML = pad( parseInt( totalSeconds / 3600 ) )
}
function pad( val ) {
var valString = val + "";
if( valString.length < 2 ) {
return "0" + valString;
} else {
return valString;
}
}
}
})();
The buttons are not working atm however. I'm not sure if this the best solution for the goal as well, so suggestions are welcome.
(function() {
"use strict";
var secondsLabel = document.getElementById('seconds'), minutesLabel = document.getElementById('minutes'), hoursLabel = document
.getElementById('hours'), totalSeconds = 0, startButton = document.getElementById('start'), stopButton = document.getElementById('stop'), resetButton = document
.getElementById('reset'), timer = null;
startButton.onclick = function() {
if (!timer) {
timer = setInterval(setTime, 1000);
}
};
stopButton.onclick = function() {
if (timer) {
clearInterval(timer);
timer = null;
}
};
resetButton.onclick = function() {
if (timer) {
totalSeconds = 0;
stop();
}
};
function setTime() {
totalSeconds++;
secondsLabel.innerHTML = pad(totalSeconds % 60);
minutesLabel.innerHTML = pad(parseInt(totalSeconds / 60));
hoursLabel.innerHTML = pad(parseInt(totalSeconds / 3600))
}
function pad(val) {
var valString = val + "";
if (valString.length < 2) {
return "0" + valString;
} else {
return valString;
}
}
})();
<html>
<head>
<script type="text/javascript">
var c=0;
var t;
var timer_is_on=0;
function timedCount()
{
document.getElementById('txt').value=c;
c=c+1;
t=setTimeout("timedCount()",1000);
}
function doTimer()
{
if (!timer_is_on)
{
timer_is_on=1;
timedCount();
}
}
function stopCount()
{
clearTimeout(t);
timer_is_on=0;
}
</script>
</head>
<body>
<form>
<input type="button" value="Start count!" onclick="doTimer()" />
<input type="text" id="txt" />
<input type="button" value="Stop count!" onclick="stopCount()" />
</form>
<p>
Click on the "Start count!" button above to start the timer. The input field will count forever, starting at 0. Click on the "Stop count!" button to stop the counting. Click on the "Start count!" button to start the timer again.
</p>
</body>
</html>

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