为什么 Mozilla 将 Object.assign polyfill 放在匿名函数中？

Question

I have a question.

In the Polyfill section of MDN page for Object.assign function.

The technical writers in Mozilla put a polyfill of Object.assign in an anonymous function:

if (typeof Object.assign != 'function') {
  (function () {
    Object.assign = function (target) {
      ...
    };
  })(); // <-- anonymous function call
}

What is the different if we just put Object.assign = function (target) { directly inside the if statement without the anonymous function here?

Why would they do that?

Answer 1

The technical writers in Mozilla

Not all editors of MDN are technical writers, it's an open wiki.

Why would they put Object.assign polyfill in an anonymous function?

There's absolutely no reason here. It might have been useful to store static values, such as a reference to Object.prototype.hasOwnProperty in there, but that was not done so the IIFE was superfluous. I've removed it .