javascript - "new" Before Anonymous Function Invocation Returning Object -

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• javascript new object (function ) vs inline invocation 3 answers

i'm reading knockoutjs source code.

i ran following line i'm not sure understand...

ko.utils = new (function () { 

generally, structure seems along lines of:

ko.utils = new (function () {     // variables declared var     return {         export:value,         export:value    };  })(); 

i don't understand construct, why new needed? do? useful for?

(i thought if function called new before name invoked constructor, , if returns object it's identical invokation without new.)

update: asked knockoutjs team on github , got back:

my guess steve didn't know wasn't needed. looking @ original commit, see lot of unnecessary news have since been removed.

it might pattern prevents this reach global context (not in case, since every variable declared var, author might wanted use general pattern create objects).

var x = new (function () {    this.foo = "bar";    return {         // whatever    }; })();  console.log(foo); // uncaught referenceerror: foo not defined   var x = (function () { // without new    this.foo = "bar";    return {         // whatever    }; })();  console.log(foo); // "bar"