Question

Encounter following lines of code, but couldn’t understand it.

What is this (/…/)(this); purpose in javascript? Does it have name for this pattern?

Code as below:

//Move.js
(function(exports){
  exports.Move = function(){

  };
})(this);

Answer 1

this pattern is an “Immediately Invoked Function Expresssion“. in short, it’s just a function that is executed immediately. the this on the end is a parameter to be sent to the inner function that will be accessed as exports

(function(exports){

    //that was "this" outside, is now "exports" in here

}(this));

in your example, we can assume that whatever this was, it’s some object that has been added a Move method to it.

some also call this pattern the “Module Pattern” in a sense that it creates a “contained environment” so that the stuff inside it is not visible to the due to a new function scope. in other words, whatever is inside sees the outside, but the outside can only see what the inside lets it see