JQuery, setTimeout not working

Question

I\'m still new to JQuery, on the way to getting my ajax example to work i got stalled with setTimeout. I have broken it down to to where it should add \".\" to the div eve

Answer 1

You've got a couple of issues here.

Firstly, you're defining your code within an anonymous function. This construct:

(function() {
  ...
)();

does two things. It defines an anonymous function and calls it. There are scope reasons to do this but I'm not sure it's what you actually want.

You're passing in a code block to setTimeout(). The problem is that update() is not within scope when executed like that. It however if you pass in a function pointer instead so this works:

(function() {
  $(document).ready(function() {update();});

  function update() { 
    $("#board").append(".");
    setTimeout(update, 1000);     }
  }
)();

because the function pointer update is within scope of that block.

But like I said, there is no need for the anonymous function so you can rewrite it like this:

$(document).ready(function() {update();});

function update() { 
  $("#board").append(".");
  setTimeout(update, 1000);     }
}

or

$(document).ready(function() {update();});

function update() { 
  $("#board").append(".");
  setTimeout('update()', 1000);     }
}

and both of these work. The second works because the update() within the code block is within scope now.

I also prefer the $(function() { ... } shortened block form and rather than calling setTimeout() within update() you can just use setInterval() instead:

$(function() {
  setInterval(update, 1000);
});

function update() {
  $("#board").append(".");
}

Hope that clears that up.