How to start and stop/pause setInterval?

Question

I\'m trying to pause and then play a setInterval loop.

After I have stopped the loop, the \"start\" button in my attempt doesn\'t seem to work :

Answer 1

See Working Demo on jsFiddle: http://jsfiddle.net/qHL8Z/3/

$(function() {
  var timer = null,
    interval = 1000,
    value = 0;

  $("#start").click(function() {
    if (timer !== null) return;
    timer = setInterval(function() {
      $("#input").val(++value);
    }, interval);
  });

  $("#stop").click(function() {
    clearInterval(timer);
    timer = null
  });
});