Question

As I don’t have much knowledge of javascript and I need your help. My problem is like this:

I am using setInterval() for increasing the value of i every after 1 minutes and I am using this code:

var i = minutes;
function decrementMin() {
    if(i>=0)
    {
        i--;
    }
    if(i==0)
    {
        alert('Minute = Congratulation your time begin now!');
    }                         
    document.getElementById('minutes').innerHTML = i + "minutes";
}
setInterval('decrementMin()',60000);

The problem is I want to show first message in <div id='minutes'></div> when page loads, but it shows the message after 1 minutes interval. If there is something that I am missing in my code please let me know.

Answer 1

Your problem is that you are setting the interval before the first message is displayed. Instead, you can call the function straight away and then set the interval. Also, you need to clear the interval once you’ve reached 0:

var i = minutes;
var intID;
function decrementMin() {
    if(i>=0)
    {
        i--;
    }
    if(i==0)
    {
        clearInterval(intID);
        alert('Minute = Congratulations my friend your time begins now!');
    }
    document.getElementById('minutes').innerHTML = i + "minutes";
}

decrementMin();
intID = setInterval(decrementMin, 60000);

This way you call your function straight away, and then set it to run every minute. Once you reach 0, you clear the interval so that the function doesn’t count to “-1”, etc.