Javascript setTimeout

Question

Can you tell me why this works:

PageMethods.UpdateForcedDisposition(forcedDisposition, a.value, SucceededCallback, FailedCallback);

When this doesn’t?

setTimeout("PageMethods.UpdateForcedDisposition(" + forcedDisposition + "," + a.value + ", SucceededCallback, FailedCallback);", 1000);

Interestingly, a similar call works with setTimeout:

setTimeout("PageMethods.UpdateSales(" + id + ", " + a.value + ", SucceededCallback, FailedCallback);", 1000);

…I’m stumped!

Answer 1

Avoid passing a string to setTimeout. Where possible, use anonymous functions:

window.setTimeout(function () {
    PageMethods.UpdateForcedDisposition(
        forcedDisposition, 
        a.value, 
        SucceededCallback, 
        FailedCallback
    );
}, 1000);

A setTimeout with a string executes in the global scope. If you're trying to reference variables from the current scope, you'll hit an error.