JavaScript Design Patterns for Coding Interviews/

...

/

Challenge: Solution Review

Challenge: Solution Review

This lesson will explain the solution to the problem from the previous coding challenge.

We'll cover the following...

Solution #

Press + to interact
class EmployeeChain 
{
  setNext(nextInChain){}
  assignWork(req){}
} 
  
class Employee
{
  constructor(name,level){
    this.name = name
    this.level = level
  }
  
  getLevel(){ 
    return this.level
  } 
  getName(){
    return this.name
  }
  
} 
  
class EasyLevelWorkHandler extends EmployeeChain
{
  constructor(){
    super()
    this.nextInChain = new EmployeeChain()
  } 
  
  setNext(nextObj){ 
    this.nextInChain = nextObj; 
  } 
  
  assignWork(req) { 
    if (req.getLevel() == "Easy") { 
      console.log("Easy work assigned to: " + req.getName()); 
    }else{ 
      this.nextInChain.assignWork(req); 
    } 
  } 
} 
  
class MediumLevelWorkHandler extends EmployeeChain
{ 
  constructor(){
    super()
    this.nextInChain = new EmployeeChain()
  } 
  
  setNext(nextObj){ 
    this.nextInChain = nextObj; 
  } 
  
  assignWork(req) { 
    if (req.getLevel() == "Medium") { 
      console.log("Medium work assigned to: " + req.getName()); 
    }else{ 
      this.nextInChain.assignWork(req); 
    } 
  } 
} 
class HardLevelWorkHandler extends EmployeeChain
{ 
  constructor(){
    super()
    this.nextInChain = new EmployeeChain()
  } 
  
  setNext(nextObj){ 
    this.nextInChain = nextObj; 
  } 
  
  assignWork(req) { 
    if (req.getLevel() == "Hard") { 
      console.log("Hard work assigned to: " + req.getName()); 
    }else{ 
      this.nextInChain.assignWork(req); 
    } 
  } 
} 
var w1 = new EasyLevelWorkHandler(); 
var w2 = new MediumLevelWorkHandler(); 
var w3 = new HardLevelWorkHandler(); 
w1.setNext(w2); 
w2.setNext(w3); 
 
const emp1 = new Employee("Joe","Easy")
const emp2 = new Employee("Anne","Medium")
const emp3 = new Employee("Shawn","Hard")
  
w1.assignWork(emp1); 
w1.assignWork(emp2); 
w1.assignWork(emp3);

Explanation

In this challenge, you had to use the chain of responsibility pattern to assign work to employees. We start by creating an employee. Here’s what the Employee class looks like:

class Employee
{
  constructor(name,level){
    this.name = name
    this.level = level
  }
  
  getLevel(){ 
    return this.level
  } 

  getName(){
    return this.name
  }
  
}

An employee will have a name ...