setInterval and clearInterval examplexxxxxxa

setInterval and clearInterval examplexxxxxxa

by Nirvanachain

HTML

<a href="#" class="startButton">Start</a>
<br />
<a href="#" class="stopButton">Stop</a>

JavaScript

(function () {
    var timer,
        startButton = document.querySelector('.startButton'),
        stopButton = document.querySelector('.stopButton');
    
    startButton.addEventListener('click', function(e) {
        if (timer) {
            clearInterval(timer);
            timer = null;
        };
        
        var count = 0;
        timer = setInterval(function() {
            count++
            console.log('count =',count);
        }, 1000);
    });
    
    stopButton.addEventListener('click', function(e) {
        if (timer) {
            clearInterval(timer);
            timer = null;
            console.log('timer stopped');
        }
    });
      
}());