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JavaScript Design Patterns for Coding Interviews

Challenge: Solution Review

Explore the mediator pattern through a solution review where HR coordinates communication between managers and workers. Understand how to implement class interactions and message passing in JavaScript to model organizational workflows.

We'll cover the following...

Solution #

Node.js
class HR {
  constructor(){
    this.employeeList = []
  }
  
  registerEmployee(employee){
    this.employeeList[employee.name] = employee
  }
  
  scheduleRaise(raise,worker, manager){
    manager.receiveMessage(worker,raise)
    var ans = manager.finalizeRaise(worker,raise)
    if(ans){
      worker. receiveRaise(raise)
    }
  }
}
class Employee{
  constructor(hr,name,position,pay){
    this.hr = hr
    this.name = name
    this.position = position
    this.pay = pay 
  }
}
class Manager extends Employee{
    constructor(hr,name,position,pay){
      super(hr,name,position,pay)
      this.hr.registerEmployee(this)
    }
    receiveMessage(worker,raise){
      console.log(`${worker.name} should get ${raise} dollar raise`)
    }
    finalizeRaise(worker,raise){
      console.log(`${worker.name}'s ${raise} dollar raise is approved`)
      return true
    }
}
class Worker extends Employee{
  constructor(hr,name,position,pay){
      super(hr,name,position,pay)
      this.hr.registerEmployee(this)
  }
  receiveRaise(raise){
    this.pay += raise
    console.log(`My new pay is ${this.pay} dollars`)
  }
}
var hr = new HR()
var employee = new Worker(hr,"Joe","Developer",1400)
var manager = new Manager(hr,"Allen","Team Lead",3000)
hr.scheduleRaise(200,employee,manager)

Explanation

In this challenge, you had to use the mediator pattern to implement the HR of an office. HR acts as a communication channel between different employees of a company, such as a manager and the workers.

Let’s start by discussing the HR class.

class HR {
  constructor(){
    this.employeeList = []
  }
  //code...
}

The constructor initializes an array employeeList that will contain all the employees in the company.

Next, it has the registerEmployee function that registers an employee by adding them to the list of employees.

registerEmployee(employee){
   this.employeeList[employee.name] = employee
}

Next, it defines the ...