Question

In the quickstart guide for the Google Drive API, the following function is called once the client library has loaded:

// Called when the client library is loaded to start the auth flow.
function handleClientLoad() {
    window.setTimeout(checkAuth, 1);
}

What is the purpose of calling setTimeout with a delay of 1 like this instead of just calling checkAuth immediately?

Answer 1

Javascript has asynchronous I/O (ajax/requests) as well as setTimeout and setInterval,

One use of running setTimeout with 1 milisecond (or 0) would be to tell that code to be run after the synchronous code following it. Here is an example

setTimeout(function(){
     alert("World");
},1); 
alert("Hello");

//alerts "Hello" then "World"

I wanted to keep my answer simple and to the point, if you’re interested, there is more details about how setTimeout works in the MDN article about it