JavaScript uses Prototype to implement object-oriented methods_javascript skills

The example in this article describes how JavaScript uses Prototype to implement object-oriented methods. Share it with everyone for your reference. The specific analysis is as follows:

Prototype is an attribute of the Function object, which points to another object. All properties and methods of this object will be inherited by the instance of the constructor.

At the same time, prototype also has a reference constructor pointing to the constructor, thus successfully forming a prototype chain structure of circular references.

We can define those unchanged properties and methods directly on the prototype object to save memory overhead.

function Cat(name, color) {
  this.name = name;
  this.color = color;
}
Cat.prototype.type = 'mammal';
Cat.prototype.eat = function() {
  console.log('eat fish');
};
var cat1 = new Cat('Kitty', 'white');
var cat2 = new Cat('Smokey', 'black');
console.log(cat1.type); // mammal
console.log(cat1.eta === cat2.eta);
// TRUE, same reference
console.log(cat1.constructor === Cat)
// TRUE, from Person.prototype

I hope this article will be helpful to everyone’s JavaScript programming design.