javascript 에서 timer 기능 사용하기

 

function startTimer(duration, display){
    var timer = duration, seconds;
    var interval = setInterval(function(){
        seconds = parseInt(timer % 60, 10);

        seconds = seconds < 10 ? "0" + seconds : seconds;
        display.textContent = seconds;

        if(timer === 0){
            clearInterval(interval);
        }
        if(--timer < 0){
            timer = duration;
        }
    }, 1000);
}

startTimer(60, document.querySelector('#timeCount'));