Javascript onMouseMove event syntax

Question

I am working on some JavaScript code and I run into this syntax that I have never seen and I am trying hard to understand but cannot find good examples.

Can someone please describe what might be going on here?

function onMouseMove(event) {
    (function(ev) {
       // some piece of code
    })(event);
}

It's an IIFE (Immediately Invoqued Function Expression). Possible duplicate of [What is the (function() { } )() construct in JavaScript?](https://stackoverflow.com/questions/8228281/what-is-the-function-construct-in-javascript) — blex, Oct 23 '19 at 21:10

score 1 · Accepted Answer · answered Oct 23 '19 at 21:10

1

This syntax is used to create an inner scope using a function and that function is immediately invoked with the event object.

answered Oct 23 '19 at 21:10

Arik

5,266
1
27
26

Of course, we all have to ask why OP would want to do this without having other code that shows us how this makes sense to do, since the `event` argument itself should be sufficient. – StackSlave Oct 23 '19 at 21:14

Javascript onMouseMove event syntax

1 Answers1