Question

I’m trying to click every item with a 200 millisecond interval, I wrote the following script however there seems to be an issue with the For Loop. Some one please tell me what you think is wrong with it.

function clickLink(elm) {
    var evt = document.createEvent('MouseEvents');
    evt.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    elm.dispatchEvent(evt);
}

function sel() {
    elms = document.getElementsByClassName('uItem');
    var inputs= elms;
    var howbig= elms.length;
    console.log(howbig);

    for (var i=250;i<elms.length;i++)
    {
        setTimeout(clickLink(inputs[i]),200)
    };

There’s 1400 uItem ‘s on the page.

Answer 1

The way your doing this won’t get you one click per 200ms, you will register all your clicks almost at the same time(the time a loop last to iterate 1000 items,almost instantly) so you basically would get your 1000+ aprox. click events fired almost simultaneously, I think that could cause issues, so to make sure they are executed once in a 200ms approx. do this:

window.i=250;
for (var i=250;i<elms.length;i++)
{
setTimeout(function() {
   clickLink(inputs[window.i]);
   window.i++;
},200 * (i-249)); //Here we make sure events are spaciated 200ms each approx.
};

UPDATE: Updated the anonymouse function to pass i to avoid closure issue noted in comments.

UPDATE 2: Added window.i inside anonymous function to workaround i scope issue

UPDATE 3: Updated my code above to fix the interval at which each click event is fired, we were using 200 * i but that is only correct if i starts at zero, here it starts at 250 so the correct form is 200 * (i-249)

In spite of some comments, the i scope issue it’s resolved using window.i , see test here https://tinker.io/98fd4/1