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javascriptclassconstructorprototypal-inheritancees6-class

Difference between constructor in ES6 class and constructor in prototype?

Both ES6 class and prototype of function have a contructor, but I'm wondering are they the same? Let me give more explanations.

So, I create a Cat function, for instance:

const Cat = function (name) {
    this.name = name;
};

The Cat has the following prototype: enter image description here This constructor can be lost if I type smth. like Cat.prototype = {};, but new Cat('Name'); will continue working. Ang we have the following syntax in ES6:

class Dog {
    constructor(name) {
        this.name = name;
    }
}

The class also has constructor and it looks just like a simple function. Since classes are just a syntactic sygar over prototype inheritance, is the constructor function in Dog class is just the same as in Cat function or these are different concepts?

Solution

  • Since classes are just a syntactic sugar over prototype inheritance, is the constructor function in Dog class just the same as in Cat function?

    Yes, the constructor-prototype relationship still works the same.

    There are a few differences though, for example Dog.prototype is not writable and Dog can only be called with new.