javascript - Invoking a function expression with hanging Parens Vs Function.prototype.call -

what difference between using standard hanging parens method invoking function expression , using .call in javascript?

i see iifes invoked like

(function(){     //your code here }).call(this); 

as opposed more standard

(function(){     //your code here })(); 

what advantage of using .call if any?

it depends on scope.

if in global scope, using .call(this) has absolutely 0 effect because this window object.

if in nested scope somewhere, , want use thisbinding (this) using .call(this) important (or storing this in variable such self or that). iife going executing @ global scope, this binding going change window. if attempt use this made in scope, , this isn't bound, referencing wrong object.

here example:

window.x = 5;    (function(){      console.log(this.x);//5    })()    var obj = {      x : 6,      test : function(){        (function(){            console.log(this.x);//5        })()      },      close : function(){       (function(){            console.log(this.x);//6       }).call(this)      }  };    obj.test();  obj.close();