how i am going to clearInterval when i press stop btn? - javascript

i am truly new with programing with javaScript so i just start to learn it, it will be good you are going to reply using a simple js code
my code does'nt stop when i press stop i want to clear the interval that i named with myTimer if i didn't put setInterval inside the function it just work directly and if there is any way to make my code more short please mentiot it.
const // my variable
myHour = document.getElementById("hours"),
myMin = document.getElementById("min"),
mySecond = document.getElementById("second"),
myMiliSecond = document.getElementById("dsecond"),
startchrono = document.getElementById("start"),
getLap = document.getElementById("lap"),
stopchrono = document.getElementById("stop"),
resetchrono = document.getElementById("reset"),
result = document.getElementById("result");
let // variable
milisecond = 0,
second = 0,
minute = 0,
hour = 0,
chronoRun = false,
round = 0;
function decoration(item) // this function is for add 0 if second or minute less than 10
{
if (String(item).length < 2) {
item = "0" + item;
}
return item;
}
function lapset() // function that create a new row in the table to save rounds
{
round++;
let // decoration add 0 if number under 10
ds = decoration(milisecond),
s = decoration(second),
m = decoration(minute),
h = decoration(hour);
if (round <= 10) {
const // insert the row in table
tr = result.insertRow(-1);
tr.insertCell(0).innerHTML = round;
tr.insertCell(-1).innerHTML = h + ":" + m + ":" + s + ":" + ds;
} else if (round <= 11) {
tr = result.insertRow(-1);
tr.insertCell(-0).innerHTML = "-";
tr.insertCell(-1).innerHTML = "you can't add any more laps";
getLap.setAttribute("disabled", "true");
}
}
function chrono() //chrono start
{
// chrono
milisecond++;
// make sure that minute, second have to be less than 60
if (milisecond > 10) {
milisecond = 0;
second++;
}
if (second > 59) {
second = 0;
minute++;
}
if (minute > 59) {
minute = 0;
hour++;
}
let // decoration add 0 if number under 10
ds = decoration(milisecond),
s = decoration(second),
m = decoration(minute),
h = decoration(hour);
myMiliSecond.innerHTML = ds;
mySecond.innerHTML = s;
myMin.innerHTML = m;
myHour.innerHTML = h;
startchrono.setAttribute("disabled", "true");
}
// function chronoStarts() {}
const myTimer = () => {
setInterval(chrono, 100);
};
const test = () => {
return clearInterval(myTimer);
};
startchrono.addEventListener("click", myTimer);
getLap.addEventListener("click", lapset);
stopchrono.addEventListener("click", test);
<!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 id="chrono">
<div id="timer">
<span id="hours" class="time">00</span>
<span class="sep">:</span>
<span id="min" class="time">00</span>
<span class="sep">:</span>
<span id="second" class="time">00</span>
<span class="sep">:</span>
<span id="dsecond" class="time">00</span>
</div>
<div id="btnarea">
<button id="start" class="btnevent">start</button>
<button id="lap" class="btnevent">lap</button>
<button id="stop" class="btnevent">stop</button>
<button id="reset" class="btnevent">reset</button>
</div>
<table id="result">
<caption>saved lap</caption>
<tbody>
<tr>
<th class="round">round</th>
<th class="laptime">time</th>
</tr>
</tbody>
</table>
</div>
<script src="newpagescript.js"></script>
</body>
</html>
and that is my html code i think every is ok with my code but if there any issue i am looking for adives

You need to get the return value of the setInterval function and then pass that value as a parameter in the clearInterval function. For example, see below:
`// function chronoStarts() {}
let intervalId = 0;
const myTimer = () => {intervalId = setInterval(chrono, 100);};
const test = () => {
clearInterval(intervalId);
};
startchrono.addEventListener("click", myTimer);
getLap.addEventListener("click", lapset);
stopchrono.addEventListener("click", test);`

Related

Trying to compare value of string that are programmatically added with javascript

I'm trying to prevent my laps from counting the same second. So I'm trying to take the current value and evaluate it as != not equal to the previous value before appending it.
Here is the function, and my HTML. Not sure if I can do anything with the ids I set up. I have jquery set up to run in my javascript, so if you have any ideas with that I would be open to listening. There are a couple of things that probably don't have a use that I have not removed yet.
Javascript Function
let seconds = 0;
let minutes = null;
let hours = null;
let startTimer = null;
let time = null;
let isRunning = (false);
let lapContainer = [];
let x;
let outputseconds;
let outputminutes;
let outputhours;
//connection to button
document.getElementById("start").addEventListener("click", start);
document.getElementById("stop").addEventListener("click", stop);
document.getElementById("reset").addEventListener("click", reset);
document.getElementById("lap").addEventListener("click", lap);
document.getElementById("resetLaps").addEventListener("click", resetLaps);
//functions
function start() {
if (isRunning === false) {
isRunning = true;
//interval
startTimer = setInterval(function () {
seconds++;
if (seconds <= 9) {
outputseconds = "0" + seconds;
document.getElementById("seconds").innerHTML = outputseconds;
} else if (seconds <= 60) {
outputseconds = seconds;
document.getElementById("seconds").innerHTML = outputseconds;
} else if (seconds >= 60) {
minutes++;
outputseconds = "00";
outputminutes = "0" + minutes;
document.getElementById("seconds").innerHTML = outputseconds;
document.getElementById("minutes").innerHTML = outputminutes;
seconds = 0;
} else if (minutes >= 9) {
outputminutes = minutes;
document.getElementById("minutes").innerHTML = outputminutes;
} else if (minutes >= 60) {
hours++;
outputminutes = "00";
outputhours = "0" + hours;
document.getElementById("minutes").innerHTML = outputminutes;
document.getElementById("hours").innerHTML = outputhours;
minutes = 0;
} else if (hours > 9) {
outputhours = hours;
document.getElementById("hours").innerHTML = outputhours;
}
}, 1000); //end of interval
} // end of if check
// should this be seperated out as a function???
let startTime = "00";
if (outputseconds > 0) {
if (outputminutes > 0) {
if (outputhours > 0) {
return outputhours + ":" + outputminutes + ":" + outputseconds;
} else {
return startTime + ":" + outputminutes + ":" + outputseconds;
} // hours
} else {
return startTime + ":" + startTime + ":" + outputseconds;
} //minutes
} else {
return startTime + ":" + startTime + ":" + startTime;
} // end of nested if seconds
} //end of start function
function stop() {
clearInterval(startTimer);
isRunning = false;
}
function reset() {
clearInterval(startTimer);
document.getElementById("seconds").innerHTML = "00";
document.getElementById("minutes").innerHTML = "00";
document.getElementById("hours").innerHTML = "00";
seconds = 0;
minutes = 0;
hours = 0;
isRunning = false;
}
function lap() {
if (isRunning === true) {
//initialize time
let lapTime = start();
//create connection to div
lapContainer = document.getElementById("lapContainer");
// how to check if they equal each other
//create element
const para = document.createElement("p");
//how many laps have been created
let i = document.getElementById("lapContainer").childElementCount;
let index = [i];
//create an index that will add an id to paragraph
para.id = index;
//add the lap to text
para.innerText = lapTime;
let laps = [];
laps = document.getElementById("lapContainer").childNodes[1].textContent;
let lastItem = laps[laps.length - 1];
let currentItem = laps[laps.length];
document.getElementById("test").innerHTML = laps;
if (currentItem !== lastItem) {
lapContainer.appendChild(para);
}
}
}
function resetLaps() {
$(lapContainer).empty();
isRunning = false;
}
HTML
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>Stopwatch</title>
<meta name="description" content="A simple stopwatch application" />
<meta name="author" content="****" />
<link rel="icon" href="/favicon.ico" />
<link rel="icon" href="/favicon.svg" type="image/svg+xml" />
<link rel="apple-touch-icon" href="/apple-touch-icon.png" />
<link rel="stylesheet" href="./css/styles.css" />
</head>
<body>
<!-- your content here... -->
<div class="menu">
Timer
Alarm
</div>
<div class="stopwatch-container">
<div class="stopwatch-wrapper">
<div class="stopwatch-button-container">
<button type="button" id="start">START</button>
<button type="button" id="stop">STOP</button>
<button type="button" id="reset">RESET</button>
<button type="button" id="lap">LAP</button>
<button type="button" id="resetLaps">RESET LAPS</button>
</div>
<div class="rectangle-container">
<div class="rectangle">
<p id="textWrapper">
<span id="hours">00</span>:<span id="minutes">00</span>:<span
id="seconds"
>00</span
>
</p>
</div>
</div>
</div>
</div>
<div class="lineBreak"></div>
<div id="lapContainer" class="lap-container"></div>
<p id="test"></p>
<script src="./scripts/scripts.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
</body>
</html>
Few things you might need to do:
1.When you set the laps array you need to get the array of texts of the all nodes, not just a text of the first node:
//laps = document.getElementById("lapContainer").childNodes[1].textContent;
laps = Array.from(document.getElementById("lapContainer").childNodes).map(node => node.textContent);
2.When you set currentItem you can not use laps[laps.length] because your new value not in the array yet and so it will return undefined. Instead you can just use your lapTime value:
let lastItem = laps[laps.length - 1];
//let currentItem = laps[laps.length];
let currentItem = lapTime;
Example:
let isRunning = Boolean(true);
let lapContainer = [];
document.querySelector('#lap').addEventListener('click', () => lap());
function lap() {
if (isRunning === true) {
//initialize time
let lapTime = start();
//create connection to div
lapContainer = document.getElementById("lapContainer");
// how to check if they equal each other
//create element
const para = document.createElement("p");
//how many laps have been created
let i = document.getElementById("lapContainer").childElementCount;
let index = [i];
//create an index that will add an id to paragraph
para.id = index;
//add the lap to text
para.innerText = lapTime;
let laps = [];
//laps = document.getElementById("lapContainer").childNodes[1].textContent;
laps = Array.from(document.getElementById("lapContainer").childNodes).map(node => node.textContent);
let lastItem = laps[laps.length - 1];
//let currentItem = laps[laps.length];
let currentItem = lapTime;
document.getElementById("test").innerHTML = laps;
if (currentItem !== lastItem) {
lapContainer.appendChild(para);
}
}
}
const start = () => new Date().toString();
<body>
<!-- your content here... -->
<div class="menu">
Timer
Alarm
</div>
<div class="stopwatch-container">
<div class="stopwatch-wrapper">
<div class="stopwatch-button-container">
<button type="button" id="start">START</button>
<button type="button" id="stop">STOP</button>
<button type="button" id="reset">RESET</button>
<button type="button" id="lap">LAP</button>
<button type="button" id="resetLaps">RESET LAPS</button>
</div>
<div class="rectangle-container">
<div class="rectangle">
<p id="textWrapper">
<span id="hours">00</span>:<span id="minutes">00</span>:<span
id="seconds"
>00</span
>
</p>
</div>
</div>
</div>
</div>
<div class="lineBreak"></div>
<div id="lapContainer" class="lap-container"></div>
<p id="test"></p>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
</body>

Another stopwatch using JS?

The code is creating a responsive page. But every time I press stop and then start again the countdown speeds up. Seconds pass like milliseconds and mins pass like seconds after about 10 or so stops and starts. What might be the issue here?
P.S. I haven't written code for the reset button.
let ms = 0;
let secs = 0;
let mins =0;
let flag = true;
var setIntID;
watchFunction =()=> {
if(flag){
ms +=4 ;
document.getElementById('msecs').innerText = `${ms}`;
if(ms == 1000){
ms =0;
secs++
document.getElementById('secs').innerText = `${secs}:`
if(secs == 60){
mins++;
document.getElementById('min').innerText = `${mins}:`;
secs = 0;
}
}}}
document.getElementById("start").addEventListener('click', function(){
flag = true;
var setIntID = setInterval(watchFunction,1);
console.log(flag) //tracker
})
document.getElementById("stop").addEventListener('click', function(){
flag = false;
console.log(flag); //tracker
clearInterval(setIntID);
})
<div id="mainDiv">
<div>
<span id="min">0:</span>
<span id="secs">0:</span>
<span id="msecs">0</span>
<div>
<button id="start">start</button>
<button id="stop">stop</button>
<button id="reset">reset</button>
</div>
</div>
</div>
You have declared setIntID as a local variable in click for the start button, and therefore it isn't cleared in the click function for the stopbutton.
let ms = 0;
let secs = 0;
let mins =0;
let flag = false;
var setIntID;
watchFunction =()=> {
if(flag){
ms +=4 ;
document.getElementById('msecs').innerText = `${ms}`;
if(ms == 1000){
ms =0;
secs++
document.getElementById('secs').innerText = `${secs}:`
if(secs == 60){
mins++;
document.getElementById('min').innerText = `${mins}:`;
secs = 0;
}
}}}
document.getElementById("start").addEventListener('click', function(){
if (flag) return;
flag = true;
setIntID = setInterval(watchFunction,1);
console.log(flag) //tracker
})
document.getElementById("stop").addEventListener('click', function(){
flag = false;
console.log(flag); //tracker
clearInterval(setIntID);
})
<div id="mainDiv">
<div>
<span id="min">0:</span>
<span id="secs">0:</span>
<span id="msecs">0</span>
<div>
<button id="start">start</button>
<button id="stop">stop</button>
<button id="reset">reset</button>
</div>
</div>
</div>
I think that solves the problem.
<!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 id="mainDiv">
<div>
<span id="min">0:</span>
<span id="secs">0:</span>
<span id="msecs">0</span>
<div>
<button id="start">start</button>
<button id="stop">stop</button>
<button id="reset">reset</button>
</div>
</div>
</div>
<script>
let ms = 0;
let secs = 0;
let mins =0;
let flag = true;
var setIntID;
var running_instance_count = 0;
watchFunction =()=> {
if(flag){
ms +=4 ;
document.getElementById('msecs').innerText = `${ms}`;
if(ms == 1000){
ms =0;
secs++
document.getElementById('secs').innerText = `${secs}:`
if(secs == 60){
mins++;
document.getElementById('min').innerText = `${mins}:`;
secs = 0;
}
}}}
document.getElementById("start").addEventListener('click', function(){
flag = true;
running_instance_count++;
if(running_instance_count == 1){
setIntID = setInterval(watchFunction,1);}
console.log(flag) //tracker
})
document.getElementById("stop").addEventListener('click', function(){
flag = false;
running_instance_count = 0;
console.log(flag); //tracker
clearInterval(setIntID);
})
document.getElementById('reset').addEventListener('click', function(){
flag = false;
ms=0; secs=0; mins=0;
running_instance_count = 0;
clearInterval(setIntID);
document.getElementById('msecs').innerText = `${0}`;
document.getElementById('secs').innerText = `${0}:`;
document.getElementById('min').innerText = `${0}:`;
})
</script>
</body>
</html>
I see a time boost now, but on it's it's first click it's actually slow at ms +=4 so I changed it to ms +=10. Also, there's no usage of the flag on the event handler which would help control the setInterval() and clearInterval() so that there is only one existing at a time. Everytime the "start" button was clicked in OP code there was another setInterval() added, therefore the time intervals combined accelerated. In the example, there's only one event handler that toggles between setInterval() and clearInterval().
let mil = 0;
let sec = 0;
let min = 0;
let flag = false;
let setIntID;
const form = document.forms.stopWatch;
const fc = form.elements;
const timer = () => {
if (flag) {
fc.milliseconds.value = mil += 10;
if (mil == 1000) {
mil = 0;
sec++;
if (sec < 10) sec = '0' + sec;
fc.seconds.value = sec + ' :';
if (sec == 60) {
min++;
if (min < 10) min = '0' + min;
fc.minutes.value = min + ' :';
sec = 0;
}
}
}
}
fc.toggle.addEventListener('click', function() {
if (!flag) {
flag = true;
setIntID = setInterval(timer, 1);
return
}
clearInterval(setIntID);
flag = false;
});
form.onreset = e => {
mil = 0;
sec = 0;
min = 0;
clearInterval(setIntID);
flag = false;
}
<form id="stopWatch">
<fieldset>
<output id="minutes">00 :</output>
<output id="seconds">00 :</output>
<output id="milliseconds">000</output><br>
<button id="toggle" type='button'>Start/Stop</button>
<button type="reset">Reset</button>
</fieldset>
</form>

Increment number of attempts and decrement number of guesses remaining

I am new to JS, I want to the code to display number of attempts made, number of guesses remaining in this simple game. I have gotten lost in the code and I don't know what I am not doing right. The const remainingAttempts returns undefined yet I want to subtract number of attempts made from maxNumberOfAttempts.
const guessInput = document.getElementById("guess");
const submitButton = document.getElementById("submit");
const resetButton = document.getElementById("reset");
const messages = document.getElementsByClassName("message");
const tooHighMessage = document.getElementById("too-high");
const tooLowMessage = document.getElementById("too-low");
const maxGuessesMessage = document.getElementById("max-guesses");
const numberOfGuessesMessage = document.getElementById("number-of-guesses");
const correctMessage = document.getElementById("correct");
let targetNumber;
let attempts = 0;
let maxNumberOfAttempts = 5;
// Returns a random number from min (inclusive) to max (exclusive)
// Usage:
// > getRandomNumber(1, 50)
// <- 32
// > getRandomNumber(1, 50)
// <- 11
function getRandomNumber(min, max) {
return Math.floor(Math.random() * (max - min)) + min;
}
function checkGuess() {
// Get value from guess input element
const guess = parseInt(guessInput.value, 10);
attempts = attempts + 1;
hideAllMessages();
if (guess === targetNumber) {
numberOfGuessesMessage.style.display = "";
numberOfGuessesMessage.innerHTML = `You made ${attempts} guesses`;
correctMessage.style.display = "";
submitButton.disabled = true;
guessInput.disabled = true;
}
if (guess !== targetNumber) {
if (guess < targetNumber) {
tooLowMessage.style.display = "";
} else {
tooHighMessage.style.display = ""; //replaced else condition statement
}
const remainingAttempts = maxNumberOfAttempts - attempts;
numberOfGuessesMessage.style.display = "";
numberOfGuessesMessage.innerHTML = `You guessed ${guess}. <br> ${remainingAttempts} guesses remaining`;
}
if (attempts === maxNumberOfAttempts) {
maxGuessesMessage.style.display = "";
submitButton.disabled = true;
guessInput.disabled = true;
}
guessInput.value = "";
resetButton.style.display = "";
}
function hideAllMessages() {
/*replaced elementIndex <= messages.length to elementIndex < messages.length*/
for (let elementIndex = 0; elementIndex < messages.length; elementIndex++) {
messages[elementIndex].style.display = "none"; //removed [elementIndex]
}
// for (let message in messages.value) {
// //used for..in to iterate through the HTML collection
// message.style.display = "none";
// }
}
function setup() {
// Get random number
targetNumber = getRandomNumber(1, 100);
console.log(`target number: ${targetNumber}`);
// Reset number of attempts
maxNumberOfAttempts = 0;
// Enable the input and submit button
submitButton.disabled = false;
guessInput.disabled = false;
hideAllMessages();
resetButton.style.display = "none";
}
submitButton.addEventListener("click", checkGuess);
resetButton.addEventListener("click", setup);
setup();
main {
display: flex;
justify-content: center;
flex-direction: column;
align-items: center;
margin: auto;
}
#guess {
width: 5em;
}
#reset {
margin: 20px;
}
<!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 href="guess.css" rel="stylesheet" />
<title>Number Guesser</title>
</head>
<body>
<main>
<h1>Guessing Game</h1>
<p>
I'm thinking of a number from 1 to 99! Can you guess it in 5 tries or
less?
</p>
<div>
<input type="number" id="guess" min="1" max="99" />
<button id="submit">Submit Guess</button>
</div>
<div>
<p class="message" id="number-of-guesses"></p>
<p class="message" id="too-high">You guessed too high. Try again.</p>
<p class="message" id="too-low">You guessed too low. Try again.</p>
<p class="message" id="max-guesses">
You reached the max number of guesses
</p>
<p class="message" id="correct">
Congratulations, You guessed correctly! <br />
Would you like to play again?
</p>
</div>
<button id="reset">Reset</button>
</main>
<script src="guess.js"></script>
</body>
</html
just increment attempts as attempts++; below const remainingAttempts = maxNumberOfAttempts - attempts;. this should solve the no. of attempts part.
In setup(), when you reset the number of attempts, you should be setting it to 5: maxNumberOfAttempts = 5;
Additionally, in checkGuess(), you should:
Make sure to decrease the number of attempts with each guess. Add maxNumberOfAttempts-- at the top of the function.
At the bottom of if (guess !== targetNumber), you can replace the variable in the message from ${remainingAttempts} to ${maxNumberOfAttempts}
, since maxNumberOfAttempts is now keeping track of the amount of attempts remaining.
Lastly, the next if statement can check if the user is out of attempts with if (maxNumberOfAttempts === 0) {...}
This eliminates the need to use 3 different 'attempt' variables since you're resetting back to '5' at each instance of setup() anyway.

how to add a save button in timer

i have no idea how to save and show out put next to stopwatch:
00:01:30 , 00:01:30 something like this.
its not important but can i make stopwatch to stop on some time like 45 min
i created a button "save" was playing whit code but i have no idea how to make it save output and show
i was trying to find in internet but could not find
I appreciate any help.
var ss = document.getElementsByClassName('stopwatch');
[].forEach.call(ss, function(s) {
var currentTimer = 0,
interval = 0,
lastUpdateTime = new Date().getTime(),
start = s.querySelector('button.start'),
stop = s.querySelector('button.stop'),
reset = s.querySelector('button.reset'),
mins = s.querySelector('span.minutes'),
secs = s.querySelector('span.seconds'),
cents = s.querySelector('span.centiseconds');
start.addEventListener('click', startTimer);
stop.addEventListener('click', stopTimer);
reset.addEventListener('click', resetTimer);
function pad(n) {
return ('00' + n).substr(-2);
}
function update() {
var now = new Date().getTime(),
dt = now - lastUpdateTime;
currentTimer += dt;
var time = new Date(currentTimer);
mins.innerHTML = pad(time.getMinutes());
secs.innerHTML = pad(time.getSeconds());
cents.innerHTML = pad(Math.floor(time.getMilliseconds() / 10));
lastUpdateTime = now;
}
function startTimer() {
if (!interval) {
lastUpdateTime = new Date().getTime();
interval = setInterval(update, 1);
}
}
function stopTimer() {
clearInterval(interval);
interval = 0;
}
function resetTimer() {
stopTimer();
currentTimer = 0;
mins.innerHTML = secs.innerHTML = cents.innerHTML = pad(0);
}
});
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Stopwatch</title>
</head>
<body>
<h1>Stopwatch</h1>
<div class="stopwatch">
<div class="controls">
<button class="start">Start</button>
<button class="stop">Stop</button>
<button class="reset">Reset</button>
<button class="save">save</button>
</div>
<div class="display">
<span class="minutes">00</span>:<span class="seconds">00</span>:<span class="centiseconds">00</span>
</div>
</div>
<script src="stopwatch.js"></script>
</body>
</html>
if i correct understand - here is solution. You still need some validations on input fields, checks on current timer and ithers, but it's worked version if user takes into account all these nuances himself.
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Stopwatch</title>
</head>
<body>
<h1>Stopwatch</h1>
<div class="stopwatch">
<div class="controls">
<button class="start">Start</button>
<button class="stop">Stop</button>
<button class="reset">Reset</button>
||stop on:
<input class="min" placeholder="min" type="text" style="width: 30px" />:
<input class="sec" placeholder="sec" type="text" style="width: 30px" />:
<input class="ms" placeholder="ms" type="text" style="width: 30px" />
<button class="save">save</button>
<div class="savedTimeBlock" style="display: none">
saved time:
<div style="display: inline-block" class="time"></div>
</div>
</div>
<div class="display">
<span class="minutes">00</span>:<span class="seconds">00</span>:<span
class="centiseconds"
>00</span
>
</div>
</div>
<script src="stopwatch.js"></script>
</body>
</html>
stopwatch.js
var ss = document.getElementsByClassName("stopwatch");
[].forEach.call(ss, function(s) {
var currentTimer = 0,
interval = 0,
lastUpdateTime = new Date().getTime(),
timeToStop = {
min:null,
sec:null,
ms:null
},
start = s.querySelector("button.start"),
stop = s.querySelector("button.stop"),
reset = s.querySelector("button.reset"),
mins = s.querySelector("span.minutes"),
secs = s.querySelector("span.seconds"),
cents = s.querySelector("span.centiseconds"),
minutes = s.querySelector(".min"),
seconds = s.querySelector(".sec"),
milliseconds = s.querySelector(".ms"),
savedTimeBlock = s.querySelector(".savedTimeBlock"),
time = s.querySelector(".time"),
save = s.querySelector(".save");
start.addEventListener("click", startTimer);
stop.addEventListener("click", stopTimer);
save.addEventListener("click", saveStopTime);
reset.addEventListener("click", resetTimer);
function pad(n) {
return ("00" + n).substr(-2);
}
function saveStopTime() {
let min = timeToStop.min = pad(+minutes.value),
sec = timeToStop.sec = pad(+seconds.value),
ms = timeToStop.ms = pad(+milliseconds.value);
if (+min || +sec || +ms) {
showSavedTimeBlock(min, sec, ms)
} else {
killSavedTimeBlock()
}
}
const showSavedTimeBlock = (min, sec, ms) => {
savedTimeBlock.style.display = 'inline-block';
time.innerText = `${min}:${sec}:${ms}:`
};
const killSavedTimeBlock = () => {
savedTimeBlock.style.display = 'none';
timeToStop.min = null;
timeToStop.sec = null;
timeToStop.ms = null;
time.innerText = ''
};
function update() {
var now = new Date().getTime(),
dt = now - lastUpdateTime;
currentTimer += dt;
var time = new Date(currentTimer);
let min = pad(time.getMinutes());
let sec = pad(time.getSeconds());
let ms = pad(Math.floor(time.getMilliseconds() / 10));
mins.innerHTML = min;
secs.innerHTML = sec;
cents.innerHTML = ms;
let ts = timeToStop;
if (ts.min === min && ts.sec === sec && ts.ms === ms) {
stopTimer()
} else {
lastUpdateTime = now;
}
}
function startTimer() {
if (!interval) {
lastUpdateTime = new Date().getTime();
interval = setInterval(update, 1);
}
}
function stopTimer() {
clearInterval(interval);
interval = 0;
}
function resetTimer() {
stopTimer();
killSavedTimeBlock()
currentTimer = 0;
mins.innerHTML = secs.innerHTML = cents.innerHTML = pad(0);
}
});

Javascript SetInterval and get value Math.random

I have just created random number. My problems is how to get value random in id and how to set price changes automatically every 5 seconds and the fluctuation amplitude less than +/- 5% compared to the current, I don't know use the setinterval function everybody help me
My code Random Price :
function generateRandomNumber(min,max) {
return (Math.random() * (max - min) + min).toFixed(2);
};
document.getElementById('price1').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price2').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price3').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price4').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price5').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price6').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price7').innerHTML = generateRandomNumber(0,99.99);
It took me a while to work around the recursion issues I was running into, before I came up with a better solution.
//<![CDATA[
// external.js
function RandNumMaker(min, max, withinPercent, secondsInterval, decimalPlaces){
this.withinPercent = withinPercent || 5;
this.secondsInterval = secondsInterval || 5;
this.decimalPlaces;
if(decimalPlaces){
this.decimalPlaces = decimalPlaces;
}
var t = this, ia = [];
function rb(mn, mx){
return mx-Math.random()*(mx-mn);
}
var pn = rb(min, max);
function rn(){
var p = 1;
if(Math.floor(Math.random()*2) === 1)p = -1
return p*(Math.floor(Math.random()*t.withinPercent)+1)/100*pn;
}
function rf(){
var r, d = t.decimalPlaces;
pn += rn();
if(pn < min || pn > max){
return rf();
}
r = pn;
if(d)r = (Math.floor(Math.round(Math.pow(10, d+1)*r)/10)/Math.pow(10, d)).toFixed(d);
return r;
}
this.setDiv = function(div){
div.innerHTML = rf(); ia = [];
var iv = setInterval(function(){
div.innerHTML = rf();
}, this.secondsInterval*1000);
ia.push(iv);
return this;
}
this.stop = function(){
for(var i=0,l=ia.length; i<l; i++){
if(ia[i]){
clearInterval(ia[i]);
}
}
ia = [];
return this;
}
}
var doc, bod, C, E, N, old = onload; // for use on other loads
onload = function(){
if(old)old();
doc = document; bod = doc.body;
C = function(tag){
return doc.createElement(tag);
}
E = function(id){
return doc.getElementById(id);
}
N = function(className, inElement){
var ii = inElement || doc;
var cN = ii.getElementsByClassName(className);
if(cN){
return cN;
}
var tn = ii.getElementsByTagName('*');
for(var i=0,e,a=[],l=tn.length; i<l; i++){
e = tn[i];
if(e.className && e.className === className)a.push(e);
}
return a;
}
var sr = new RandNumMaker(0, 99.99), sl = N('slow');
var fr = new RandNumMaker(0, 99.99), fs = N('fast');
sr.decimalPlaces = 2;
fr.secondsInterval = 0.1; fr.withinPercent = 5;
for(var i=0,l=sl.length; i<l; i++){
sr.setDiv(sl[i]);
}
for(var i=0,l=fs.length; i<l; i++){
fr.setDiv(fs[i]);
}
}
//]]>
/* extrnal.js */
html,body{
padding:0; margin:0;
}
body{
background:#000; overflow-y:scroll;
}
.main{
width:940px; background:#fff; padding:20px; margin:0 auto;
}
<!DOCTYPE html>
<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en' lang='en'>
<head>
<meta http-equiv='content-type' content='text/html;charset=utf-8' />
<meta name='viewport' content='width=device-width' />
<title>test</title>
<link type='text/css' rel='stylesheet' href='external.css' />
<script type='text/javascript' src='external.js'></script>
</head>
<body>
<div class='main'>
<div class='slow'></div>
<div class='slow'></div>
<div class='slow'></div>
<div class='slow'></div>
<div class='slow'></div>
<div class='slow'></div>
<div class='slow'></div>
<hr />
<div class='fast'></div>
<div class='fast'></div>
<div class='fast'></div>
<div class='fast'></div>
</div>
</body>
</html>
Should work now!
After you create a new RandNumMaker(min, max) then you can set randomNumMarkerInstance.decimalPlaces, randomNumMakerInstance.withinPercent and randomNumMakerInstance.secondsInterval using simple assignment. randomNumMakerInstance.setDiv(div) starts it. randomNumMakerInstance.stop() stops it.
I think you can understand this code.
I tried to keep your code.
The key is to use setInterval function.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<script>
function generateRandomNumber(min,max) {
return (Math.random() * (max - min) + min).toFixed(2);
};
function assignData(){
document.getElementById('price1').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price2').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price3').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price4').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price5').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price6').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price7').innerHTML = generateRandomNumber(0,99.99);
setInterval(assignData, 5000); //every 5 seconds
}
</script>
<body onload="assignData()">
<h2 id="price1"></h2>
<h2 id="price2"></h2>
<h2 id="price3"></h2>
<h2 id="price4"></h2>
<h2 id="price5"></h2>
<h2 id="price6"></h2>
<h2 id="price7"></h2>
</body>
</html>
My interpretation of your question: all elements to start with a random value between 0 and 99.99, and then every five seconds one randomly selected element is to be updated, changing its value by a random amount within 5% of its current value. (If you want to update every element every five seconds then change the random selection to be a loop instead.)
For simplicity in the demo snippet (click "Run code snippet" to see it work), I've used a group of <li> elements which I select with .querySelectorAll("li"), but if you really want to do it using element IDs you could say .querySelectorAll("#price1,#price2,#price3,#price4,#price5,#price6,#price7").
function generateRandomNumber(min,max) {
return (Math.random() * (max - min) + min).toFixed(2);
}
// get list of elements:
var elements = document.querySelectorAll("li");
// populate all elements initially:
[].forEach.call(elements, function(el) {
el.innerHTML = generateRandomNumber(0,99.99);
});
// update an element at random every second:
setInterval(function update() {
var element = elements[Math.floor(Math.random() * elements.length)];
var currentVal = +element.innerHTML;
element.innerHTML = generateRandomNumber(currentVal * 0.95, currentVal * 1.05);
}, 1000);
<ul>
<li></li><li></li><li></li><li></li><li></li><li></li><li></li>
</ul>
Note that five second intervals seemed too slow for a demo, so I've used one second (1000ms) here.
Further reading:
.querySelectorAll()
Array .forEach() method
Function.prorotype.call()
Math.floor()
unary plus operator
Hope this will help.
<body>
<p id="price1"></p>
<p id="price2"></p>
<p id="price3"></p>
<p id="price4"></p>
<p id="price5"></p>
<p id="price6"></p>
<p id="price7"></p>
</body>
<script>
//set initial random number for the elements
document.getElementById('price1').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price2').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price3').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price4').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price5').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price6').innerHTML = generateRandomNumber(0,99.99);
document.getElementById('price7').innerHTML = generateRandomNumber(0,99.99);
//set random number to elements with fluctuation +/- 5%
setRandomToElements()
function generateRandomNumber(min,max) {
return (Math.random() * (max - min) + min).toFixed(2);
};
function setRandomToElements(){
//get current prices
var currentPrice1 = parseInt(document.getElementById('price1').innerHTML);
var currentPrice2 = parseInt(document.getElementById('price2').innerHTML);
var currentPrice3 = parseInt(document.getElementById('price3').innerHTML);
var currentPrice4 = parseInt(document.getElementById('price4').innerHTML);
var currentPrice5 = parseInt(document.getElementById('price5').innerHTML);
var currentPrice6 = parseInt(document.getElementById('price6').innerHTML);
var currentPrice7 = parseInt(document.getElementById('price7').innerHTML);
var fluctuation = 0.05;//5%
//random new numbers +/-5% current price
document.getElementById('price1').innerHTML = generateRandomNumber(currentPrice1-(currentPrice1*fluctuation), currentPrice1+(currentPrice1*fluctuation));
document.getElementById('price2').innerHTML = generateRandomNumber(currentPrice2-(currentPrice2*fluctuation), currentPrice2+(currentPrice2*fluctuation));
document.getElementById('price3').innerHTML = generateRandomNumber(currentPrice3-(currentPrice3*fluctuation), currentPrice3+(currentPrice3*fluctuation));
document.getElementById('price4').innerHTML = generateRandomNumber(currentPrice4-(currentPrice4*fluctuation), currentPrice4+(currentPrice4*fluctuation));
document.getElementById('price5').innerHTML = generateRandomNumber(currentPrice5-(currentPrice5*fluctuation), currentPrice5+(currentPrice5*fluctuation));
document.getElementById('price6').innerHTML = generateRandomNumber(currentPrice6-(currentPrice6*fluctuation), currentPrice6+(currentPrice6*fluctuation));
document.getElementById('price7').innerHTML = generateRandomNumber(currentPrice7-(currentPrice7*fluctuation), currentPrice7+(currentPrice7*fluctuation));
setInterval(setRandomToElements, 5000);
}
</script>
Fiddle

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