Parameters in bracket after a javascript function

Question

I found a solution for google maps marker on stack-overflow. Here is the link. Google Maps API Multiple Markers with Infowindows

google.maps.event.addListener(marker,'click', (function(marker,content,infowindow){ 
return function() {
    infowindow.setContent(content);
    infowindow.open(map,marker);
};
})(marker,content,infowindow));

My question is: What is the purpose of (marker,content,infowindow) being placed behind the javascript function? And what is it called? Thank you very much in advanced.

score 1 · Answer 1 · answered Sep 11 '18 at 14:40

1

That is a self invoking function - that means it is immediately called with these parameters, just after declaration

answered Sep 11 '18 at 14:40

Daut

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1

Thanks a lot for answering my question. – Stan Oct 18 '18 at 14:21

score 1 · Accepted Answer · answered Sep 11 '18 at 14:42

1

It's a IIFE (Immediately Invoked Function Expression), the second parenthesis invokes the function and allows you to pass arguments to the function

(function () {
    //statements
})();

Check docs here

answered Sep 11 '18 at 14:42

Damian Peralta

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Thank you very much for your time. Appreciate it much – Stan Oct 18 '18 at 14:20

score 1 · Answer 3 · answered Sep 11 '18 at 14:43

Please see the answer by Damian for the official name.

However, this is simply executing the function created by executing the first function.

If we breakup the code into multiple lines, it may make more sense:

const makeAFuction = function(marker,content,infowindow){ 
  return function() {
    infowindow.setContent(content);
    infowindow.open(map,marker);
  };
}
const listener = makeAFunction(marker,content,infowindow);
google.maps.event.addListener(marker,'click', listener);

Thanks for explaining in details. Helpful to a beginner like me =) — Stan, Oct 18 '18 at 14:22

Parameters in bracket after a javascript function

3 Answers3