We Keep Coding

Create a simple 2 minutes countdown

I want to make a count of 2 minutes, but I want to give you click to the button "Start", so far, and managed to make it work, but I have an error in the minutes does not run as well back but that appears NaN:seconds.
I show them the code that i am working on.
var timeoutHandle;
function countdown(minutes) {
var seconds = 60;
var mins = minutes
function tick() {
var counter = document.getElementById("timer");
var current_minutes = mins-1
seconds--;
counter.innerHTML =
current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
if( seconds > 0 ) {
timeoutHandle=setTimeout(tick, 1000);
} else {
if(mins > 1){
// countdown(mins-1); never reach “00″ issue solved:Contributed by Victor Streithorst
setTimeout(function () { countdown(mins - 1); }, 1000);
}
document.getElementById("timer").innerHTML = "Finished"
}
}
tick();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.0/jquery.min.js"></script>
<div class="tempo-completo">
<div id="timer">2:00</div>
<button onclick="countdown()">INICIAR</button>
</div>

You are not passing in the number of minutes to the countdown() function.
var timeoutHandle;
function countdown(minutes) {
var seconds = 60;
var mins = minutes
function tick() {
var counter = document.getElementById("timer");
var current_minutes = mins-1
seconds--;
counter.innerHTML =
current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
if( seconds > 0 ) {
timeoutHandle=setTimeout(tick, 1000);
} else {
if(mins > 1){
// countdown(mins-1); never reach “00″ issue solved:Contributed by Victor Streithorst
setTimeout(function () { countdown(mins - 1); }, 1000);
}
document.getElementById("timer").innerHTML = "Finished"
}
}
tick();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.0/jquery.min.js"></script>
<div class="tempo-completo">
<div id="timer">2:00</div>
<button onclick="countdown(2)">INICIAR</button>
</div>

Jeremy Harris' answer is working perfectly fine, but i would like to propose another one.
Don't use setTimeout to make an interval function, use setInterval. Using setTimeout with a recursive loop is overall less precise
With that in mind i've tweek your code to incorporate this idea.
var timeoutHandle;
function countdown(minutes) {
var seconds = 60;
var mins = minutes
var counter = document.getElementById("timer");
var current_minutes = mins-1
// we create an interval variable to clear it later
// we also use an arrow function to have access to variable
// outside of the current function's scope.
let interval = setInterval(() => {
seconds--;
counter.innerHTML =
current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
// our seconds have run out
if(seconds <= 0) {
// our minutes have run out
if(current_minutes <= 0) {
// we display the finished message and clear the interval so it stops.
counter.innerHTML = "Finished"
clearInterval(interval);
} else {
// otherwise, we decrement the number of minutes and change the seconds back to 60.
current_minutes--;
seconds = 60;
}
}
// we set our interval to a second.
}, 1000);
}
<div class="tempo-completo">
<div id="timer">2:00</div>
<button onclick="countdown(2)">INICIAR</button>
</div>

stopwatch not functioning properly

I'm just starting with javascript, I've been trying to make a simple stopwatch, I found a couple of ways to do it , then I came across this function ... the code doesn't work as a stopwatch unless we return a function , can somebody help me understand why????
for (var i = 1; i <= 5; i++) {
var tick = function(i) {
return ()=>{console.log(i);}
};
setTimeout(tick(i), 500 * i);
}

You should use setInterval and clearInterval for your case.
var i = 10;
var tick = function(i) {
return ()=>{
console.log(i--);
if(i == 0) clearInterval(timer);
}
};
var timer = setInterval(tick(i), 500);
If you want to have stopwatch, you can clearInterval in stop button click event
function stop(){
clearInterval(timer);
}
Update:
I combined Start and Stop in only one button using addEventListener and removeEventListener
var i = 1;
var timer;
var tick = function(i) {
return ()=>{
console.clear();
console.log(i++);
//if(i == 0) clearInterval(timer);
}
};
function start(){
document.getElementById("start").disabled = true;
document.getElementById("stop").disabled = false;
timer = setInterval(tick(i), 500);
}
function stop(){
clearInterval(timer);
document.getElementById("stop").disabled = true;
document.getElementById("start").disabled = false;
}
(function() {
document.getElementById("start2").addEventListener("click", start2);
})();
function start2(){
timer = setInterval(tick(i), 500);
document.getElementById("start2").innerHTML = "Stop";
document.getElementById("start2").removeEventListener("click", start2);
document.getElementById("start2").addEventListener("click", stop2);
}
function stop2(){
clearInterval(timer);
document.getElementById("start2").innerHTML = "Start";
document.getElementById("start2").removeEventListener("click", stop2);
document.getElementById("start2").addEventListener("click", start2);
}
<button id="start" onclick="start()">Start</button>
<button id="stop" onclick="stop()">Stop</button>
<h2>Combine Start and Stop</h2>
<button id="start2" >Start</button>

Because setTimeout first parameter has to be a function.
Your code works because it immediately executes the tick(i) function, which returns a function and that one is used 500ms later as callback.

below code will help you
<h1><time>00:00:00</time></h1>
<button id="start">start</button>
<button id="stop">stop</button>
<button id="clear">clear</button>
</pre>
<script>
var h1 = document.getElementsByTagName('h1')[0],
start = document.getElementById('start'),
stop = document.getElementById('stop'),
clear = document.getElementById('clear'),
seconds = 0, minutes = 0, hours = 0,
t;
function add() {
seconds++;
if (seconds >= 60) {
seconds = 0;
minutes++;
if (minutes >= 60) {
minutes = 0;
hours++;
}
}
h1.textContent = (hours ? (hours > 9 ? hours : "0" + hours) : "00") + ":" + (minutes ? (minutes > 9 ? minutes : "0" + minutes) : "00") + ":" + (seconds > 9 ? seconds : "0" + seconds);
timer();
}
function timer() {
t = setTimeout(add, 1000);
}
start.onclick = function(){
timer();
start.disabled=true;
}
/* Stop button */
stop.onclick = function() {
clearTimeout(t);
start.disabled=false;
}
/* Clear button */
clear.onclick = function() {
h1.textContent = "00:00:00";
seconds = 0; minutes = 0; hours = 0;
}
</script>

How to start a eggtimer after clearInterval()?

A have an eggtimer which can be stopped after clicking on the button "stop". What I want is making this timer working again (from the point where it stopped) after clicking "cancel" in a confirm box. Any sugestions? Thanks for help :)
<!DOCTYPE html>
<html>
<body onload="timer();">
<button onclick="exit();">stop</button>
<p id="seconds">30</p>
<script type="text/javascript">
var clock;
function timer () {
var start = new Date().getTime();
clock = setInterval(function() {
var seconds = Math.round(30 - (new Date().getTime() - start) / 1000);
if (seconds >= 0)
document.getElementById('seconds').innerHTML = seconds;
else
clearInterval(clock);
if (seconds==0) {window.location.href="something.com";
return;
}
}, 1000);
}
function exit(){
clearInterval(clock);
var result = confirm("Are you leaving?");
if (result == true) {
window.location.href="somewhere.com";
}
else {
timer();} // <-- ????
}
</script>
</body>
</html>

You can create a variable that holds in what seconds you are ;
var sec = seconds;
Change your function timer with the timer you want to start as a paramerter
function timer (time)
var clock;
var sec;
function timer (time) {
var start = new Date().getTime();
clock = setInterval(function() {
var seconds = Math.round(time - (new Date().getTime() - start) / 1000);
sec = seconds;
if (seconds >= 0){
document.getElementById('seconds').innerHTML = seconds;
}
else{
clearInterval(clock);
}
if (seconds==0){
window.location.href="something.com";
return;
}
}, 1000);
}
function exit(){
clearInterval(clock);
var result = confirm("Are you leaving?");
if (result == true) {
window.location.href="somewhere.com";
}
else {
console.log(sec);
timer(sec);} // <-- ????
}
<body onload="timer(30);">
<button onclick="exit();">stop</button>
<p id="seconds">30</p>
</body>

Here's a working example.
I moved the seconds variable outside the function so it persists and can be used to re-start the timer.
Also, I added an argument to the timer() function so the count down amount can be changed.
Note that the granularity is at the second level, so the actual count down time might eventually be longer than 30 seconds, but I believe it is acceptable in this use case.
var clock;
var seconds;
function timer(wait) {
var start = new Date().getTime();
clock = setInterval(function() {
seconds = Math.round(wait - (new Date().getTime() - start) / 1000);
if (seconds >= 0)
document.getElementById('seconds').innerHTML = seconds;
else
clearInterval(clock);
if (seconds == 0) {
window.location.href = "something.com";
return;
}
}, 1000);
}
function exit() {
clearInterval(clock);
var result = confirm("Are you leaving?");
if (result == true) {
window.location.href = "somewhere.com";
} else {
timer(seconds);
} // <-- ????
}
timer(30);
<button onclick="exit();">stop</button>
<p id="seconds">30</p>

getting error: Cannot set property 'innerHTML' of null

i keep getting error said: Cannot set property 'innerHTML' of null.
i try to change innerHTML ->innerText. still not working.
what am i missing here???
function countdown(minutes) {
var seconds = 60;
var mins = minutes
function tick() {
var counter = document.getElementById("timer");
var current_minutes = mins-1;
seconds--;
counter.innerHTML =
current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
if( seconds > 0 ) {
setTimeout(tick, 1000);
} else {
if(mins > 1){
// countdown(mins-1); never reach “00″ issue solved:Contributed by
Victor Streithorst
setTimeout(function () { countdown(mins - 1); }, 1000);
}
}
}
tick();
}
countdown(3);
html
<div id="timer"></div>

You're calling countdown(), which calls tick(), which calls document.getElementById("timer"), before that element has even been parsed.
Try doing it like this:
<div id="timer"></div>
<script type="text/javascript">
function countdown(minutes) {
var seconds = 60;
var mins = minutes
function tick() {
var counter = document.getElementById("timer");
var current_minutes = mins-1
seconds--;
counter.innerHTML = current_minutes.toString() + ":" + (seconds < 10 ? "0" : "") + String(seconds);
if( seconds > 0 ) {
setTimeout(tick, 1000);
} else {
if(mins > 1) {
// countdown(mins-1);
setTimeout(function () { countdown(mins - 1); }, 1000);
}
}
}
tick();
}
countdown(3);
</script>
In this case, order matters. You want to make sure the document has encountered that element before accessing it via the DOM.

Time to start only after button click

http://jsfiddle.net/Bwdfw/98/
is there a way to start timer only after a button is clicked in the given jsfiddle link
http://jsfiddle.net/Bwdfw/98/
var seconds=0;
var Score=0;
var index=0;
countdown(60);
function countdown(sec) {
seconds = sec;
tick();
}
function tick() {
var counter = document.getElementById("timer");
seconds--;
counter.innerHTML = "Time : " + String(seconds);
if(seconds>60 && Score<30)
{
alert("Not enough Score");
}
if( seconds > 0 ) {
setTimeout(tick, 1000);
}
}

Have a function inside the click handler and a variable which states if the function has started or not.
Also you can club the click events inside a single handler and the index can be stored as part of the data-* attributes which reduces duplicated code.
Javascript
//Timer //
var seconds = 0,
Score = 0,
index = 0,
timerStarted = false;
function countdown(sec) {
seconds = sec;
tick();
}
function tick() {
var counter = document.getElementById("timer");
seconds--;
counter.innerHTML = "Time : " + String(seconds);
if (seconds > 60 && Score < 30) {
alert("Not enough Score");
}
if (seconds > 0) {
setTimeout(tick, 1000);
}
}
$("#one, #two, #three").click(function () {
if(!timerStarted) {
countdown(60);
timerStarted = true;
}
var dataIndex = $(this).data('index');
if (index == dataIndex) {
Score++;
if(dataIndex == 2) {
index = 0;
} else {
index++;
}
}
$("#score").html("Score: " + Score);
});
HTML
<div id="timer"></div>
<div id="score">Score: 0</div>
<button id="one" type="button" data-index="0">Button1</button>
<button id="two" type="button" data-index="2">Button2</button>
<button id="three" type="button" data-index="1">Button3</button>
Check Fiddle

var seconds=0;
var Score=0;
var index=0;
var started = false;
function countdown(sec) {
seconds = sec;
tick();
}
function tick() {
var counter = document.getElementById("timer");
seconds--;
counter.innerHTML = "Time : " + String(seconds);
if(seconds>60 && Score<30)
{
alert("Not enough Score");
}
if( seconds > 0 ) {
setTimeout(tick, 1000);
}
}
$("button").click(function(){
if(!started){
started = true;
countdown(60);
}
});

You could generate custom event after click
$(window).trigger('clicked');
$(window).on('clicked', function() {
setTimeout(tick, 1000);
});
http://jsfiddle.net/Bwdfw/100/

Just remember to check if the countdown has not started yet.
$("button").click(function(){
});
This will add a handler to all the buttons in your DOM, then just check the status of the countdown.
Check this fiddle:
http://jsfiddle.net/eddiarnoldo/Bwdfw/102/