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Object() vs. Function()

Time:05-07

It is my understanding that pretty much everything in JS is an object and that constructors are one way to make a new object. I know that data types like Array, Function, and Objects all have to use the new keyword, thereby making them objects and on the backend works like new Array(), new Function() or new Object() Please correct me if I am wrong. This is where things got confusing for me. I assigned x to an array [1, 2, 3, 4]. When I inspected x, it showed that the [[prototype]] is an Array and the constructor is the Array() object. At the end, it showed the Array() object's prototype which is Object and the constructor for the Object to be Object(). I understood everything until I typed in Object.constructor and the result was Function(). Shouldn't it be Object(), instead of Function()? If the constructor of an object is new Object(), why is it telling me that Function is the constructor? That way if I create a new object it will be instantiated like this: let x = new Function(), yes? That was not the only one. Every primitive and reference data type gave the same result. Here is the code. I was so happy when I thought I grasped this knowledge and then I somehow I broke it. Hmmm, much like coding....lol. Thanks in advance for explaining.

let x = [1, 2, 3, 4];

undefined

x;

(4) [1, 2, 3, 4]

   0: 1

   1: 2

   2: 3

   3: 4

length: 4

  **[[Prototype]]: Array(0)**

  at: ƒ at()

  concat: ƒ concat()

  **constructor: ƒ Array()**

  copyWithin: ƒ copyWithin()

  entries: ƒ entries()

  every: ƒ every()

  ...Many other Array methods...

  **[[Prototype]]: Object**

     **constructor: ƒ Object()**

     hasOwnProperty: ƒ hasOwnProperty()

     isPrototypeOf: ƒ isPrototypeOf()

     propertyIsEnumerable: ƒ propertyIsEnumerable()

     toLocaleString: ƒ toLocaleString()

    toString: ƒ toString()

    valueOf: ƒ valueOf()

    __defineGetter__: ƒ __defineGetter__()

    __defineSetter__: ƒ __defineSetter__()

    __lookupGetter__: ƒ __lookupGetter__()

    __lookupSetter__: ƒ __lookupSetter__()

    __proto__: (...)

    get __proto__: ƒ __proto__()

    set __proto__: ƒ __proto__()

**Array.constructor;**

*ƒ Function() { [native code] }*

**Object.constructor;**

*ƒ Function() { [native code] }*

**Function.constructor;**

*ƒ Function() { [native code] }*

**String.constructor;**

*ƒ Function() { [native code] }*

**Boolean.constructor;**

*ƒ Function() { [native code] }*

**Number.constructor;**

*ƒ Function() { [native code] }*

CodePudding user response:

Object is a function used to construct objects. Since it is a function, its own constructor is Function.

CodePudding user response:

I think you could think this way, constructor is a function that return an instance of object.

Now why you add new is that so you create a new instance of the object.

Now class and function in js is almost the same.

Look below example

object example

class test {
  constructor(name){
    this.name = name;
  }
  
  getName(){
    return this.name;
  }
}


console.log(new test("hej").getName())

Function Example

function test(name){
  this.name = name;
}

test.prototype.getName =function(){
  return this.name;
}

console.log(new test("hej").getName())

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