你如何在 JavaScript 中将一个类表示为一个函数

Question

Per Classes in MDN

Classes are in fact "special functions"

How would something like

class Foo {
  constructor(x) {
    this.x = x;
  }

  foo() {}

}

be translated to just function (ignoring the "hoisting" feature)

Answer 1

 // declare the "class" function Foo (x) { this.x = x; } // declare the instance method Foo.prototype.foo = function () { return 'i am foo'; } // create an instance const f = new Foo(42); // invoke its methods console.log(f.foo()); // 'i am foo' // access its properties console.log(fx); // 42

Answer 2

Non hoisted , (as much as constructor functions based on class syntax are not hoisted ,) due to an immediately invoked function expression (IIFE) which serves as module pattern ...

const Foo = (function () {    //  class Foo {
                              //
  function Foo(x) {           //    constructor(x) {
    this.x = x;               //      this.x = x;
  }                           //    }
  function foo() {            //    foo() {
  }                           //
  Foo.prototype.foo = foo;    //    }
                              //
  return Foo;                 //
                              //
}());                         //  }

Answer 3

Well really everything is objects - a class is simply a blueprint for an object that has some methods and some values. It's all objects with features that can either store values or transform values.

A class is something - a function does something. Calling it a special function is if anything unnecessary at best and confusing at worst.

Basically - don't worry about it.