parent constructor example in js

Example 1: super in javascirpt

class Rectangle {
  constructor(height, width) {
    this.name = 'Rectangle';
    this.height = height;
    this.width = width;
  }
  sayName() {
    console.log('Hi, I am a ', this.name + '.');
  }
  get area() {
    return this.height * this.width;
  }
  set area(value) {
    this._area = value;
  }
}

class Square extends Rectangle {
  constructor(length) {
    this.height; // ReferenceError, super needs to be called first!

    // Here, it calls the parent class's constructor with lengths
    // provided for the Rectangle's width and height
    super(length, length);

    // Note: In derived classes, super() must be called before you
    // can use 'this'. Leaving this out will cause a reference error.
    this.name = 'Square';
  }
}

Example 2: javascript inherit function

function inherit(c, p) {
        Object.defineProperty(c, 'prototype', {
            value: Object.assign(c.prototype, p.prototype),
            writable: true,
            enumerable: false
        });

        Object.defineProperty(c.prototype, 'constructor', {
            value: c,
            writable: true,
            enumerable: false
        });
    }
// Or if you want multiple inheritance

function _inherit(c, ...p) {
        p.forEach(item => {
            Object.defineProperty(c, 'prototype', {
                value: Object.assign(c.prototype, item.prototype),
                writable: true,
                enumerable: false
            });
        })

        Object.defineProperty(c.prototype, 'constructor', {
            value: c,
            writable: true,
            enumerable: false
        });
    }