javascript函数后括号中的参数

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.

Answer 1

这是一个自调用函数 - 这意味着在声明之后立即使用这些参数调用它

Answer 2

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

Answer 3

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);