JS: window.setInterval still running in the background?

My code is like:

window.setInterval(updateSeconds, 1000);
function updateSeconds() {
    var remainingSeconds = $('#seconds').html() - 1;
    if(remainingSeconds < 0) {
        remainingSeconds = 0;
    }
 开发者_开发问答   $('#seconds').html(remainingSeconds);
    if(remainingSeconds == 0) {
        //stop calling updateSeconds
    }
}

There is no issue, except that setInterval will still keep calling updateSeconds(), is there a way to stop it?

Yes, you can use clearInterval to stop a timer:

// Added `var handle`:
var handle = window.setInterval(updateSeconds, 1000);
function updateSeconds() {
    var remainingSeconds = $('#seconds').html() - 1;
    if(remainingSeconds < 0) {
        remainingSeconds = 0;
    }
    $('#seconds').html(remainingSeconds);
    if(remainingSeconds == 0) {
        //stop calling updateSeconds
        window.clearInterval(handle);  // <== added
        handle = 0;                    // <== added
    }
}

If your code is at global scope, you probably don't want to create a new global variable called handle. You can avoid that by wrapping it in a function and then executing the function immediately:

(function() {
    var handle = window.setInterval(updateSeconds, 1000);
    function updateSeconds() {
        var remainingSeconds = $('#seconds').html() - 1;
        if(remainingSeconds < 0) {
            remainingSeconds = 0;
        }
        $('#seconds').html(remainingSeconds);
        if(remainingSeconds == 0) {
            //stop calling updateSeconds
            window.clearInterval(handle);
            handle = 0;
        }
    }
})();

Now handle and updateSeconds are private to the anonymous function. (Obviously if you need to call updateSeconds from somewhere else, making it private would be a problem.)

But if they're already inside something (an event handler function, perhaps), you've already got a private scope there and don't need to do that.