JS: Function.prototype

What Is Function.prototype

Function.prototype is the value of the property key "prototype" of the function Function. 〔see Function Object〕

Function.hasOwnProperty("prototype")

Type

Type of Function.prototype is function object.

typeof Function.prototype === "function"

Function.prototype(args) is not useful. It takes any number of arguments, and always return undefined.

// Function.prototype() takes any arg, return undefined

console.log(Function.prototype() === undefined);
console.log(Function.prototype(3) === undefined);
console.log(Function.prototype(3, 4) === undefined);
console.log(Function.prototype({}) === undefined);

Parent

Parent of Function.prototype is Object.prototype .

Reflect.getPrototypeOf(Function.prototype) === Object.prototype

Purpose

Function.prototype is the parent of all function objects.

console.log(Reflect.getPrototypeOf(function f() {}) === Function.prototype);
console.log(Reflect.getPrototypeOf((x) => 3) === Function.prototype);

〔see Prototype and Inheritance〕

Properties

Value Properties

• constructor
• name

Function Properties

• call
• apply
• bind
• toString
• [Symbol.hasInstance]