How can I pass a parameter to a setTimeout() callback?

Question

I have some JavaScript code that looks like:

function statechangedPostQuestion()
{
  //alert("statechangedPostQuestion");
  if (xmlhttp.readyState==         


        

Answer 1

Replace

 setTimeout("postinsql(topicId)", 4000);

with

 setTimeout("postinsql(" + topicId + ")", 4000);

or better still, replace the string expression with an anonymous function

 setTimeout(function () { postinsql(topicId); }, 4000);

EDIT:

Brownstone's comment is incorrect, this will work as intended, as demonstrated by running this in the Firebug console

(function() {
  function postinsql(id) {
    console.log(id);
  }
  var topicId = 3
  window.setTimeout("postinsql(" + topicId + ")",4000); // outputs 3 after 4 seconds
})();

Note that I'm in agreeance with others that you should avoid passing a string to setTimeout as this will call eval() on the string and instead pass a function.