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JavaScript Design Patterns for Coding Interviews

Challenge: Solution Review

Explore how to implement and use a ReverseIterator class to traverse JavaScript hashmaps in reverse order. Learn essential behavioral pattern methods like hasprevElement, last, and previous to manage object communication effectively. Understand this solution to apply design patterns during interview challenges.

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Solution

Node.js
class ReverseIterator {
  constructor(elements) {
	    this.keys = Object.keys(elements)
      this.index = this.keys.length - 1
      this.elements = elements
   }
  hasprevElement() {
    return this.index >=0
  }
  last(){
	  this.index = this.keys.length - 1 
	  return this.elements[this.keys[this.index]]
  }
  previous(){
    if(this.index >= 0){
      return  this.elements[this.keys[--this.index]]	  	
    }else{
      return null
    }
	
  }
}
function reverseIterate(items){
    var iter = new ReverseIterator(items)
    
    for(var i = iter.last();iter.hasprevElement(); i = iter.previous()){
		  console.log(i)
    }	    
}
reverseIterate({'name': 'Anne', 'age': '23', 'gender': 'Female', 'Occupation': 'Engineer'})

Explanation

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