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

As you've tagged this jQuery ...

First, put IDs on your input buttons and remove the inline handlers:

Then keep all of your state and functions encapsulated in a closure:

EDIT updated for a cleaner implementation, that also addresses @Esailija's concerns about use of setInterval().

$(function() {
    var timer = null;
    var input = document.getElementById('input');

    function tick() {
        ++input.value;
        start();        // restart the timer
    };

    function start() {  // use a one-off timer
        timer = setTimeout(tick, 1000);
    };

    function stop() {
        clearTimeout(timer);
    };

    $('#start').bind("click", start); // use .on in jQuery 1.7+
    $('#stop').bind("click", stop);

    start();  // if you want it to auto-start
});

This ensures that none of your variables leak into global scope, and can't be modified from outside.

(Updated) working demo at http://jsfiddle.net/alnitak/Q6RhG/