JavaScript: How to get setInterval() to start now? [duplicate]

Question

I am using the setInterval() function to call a function every 20 seconds. However, one thing I noticed is that it the first time setInterval() actually calls the function is at 20 seconds (and not when setInterval() is called). Here is my current workaround:

dothis(); var i = setInterval(dothis, 20000); 

Is there any way to achieve this without having this duplicate code?

Answer 1

Your method is THE normal way way of doing it.

If this comes up over and over, you could make a utility function that would execute the handler first and then set the interval:

function setIntervalAndExecute(fn, t) {     fn();     return(setInterval(fn, t)); } 

Then, in your code, you could just do this:

var i = setIntervalAndExecute(dothis, 20000);