function reverseString(str){
  let i = str.length - 1
  let rverse = ""
	while(i >= 0){
  	rverse = rverse + str[i]
    i--
  }
  return rverse
}

const word = "My name is chandan"
let i = 0
let arr = []
let pushStr = ""

while(i <= word.length){
  if(/\s+/.test(word[i]) || i === word.length){ 
  	arr.unshift(reverseString(pushStr))
    pushStr = ""
  }else{
  	pushStr = pushStr + word[i]
  }
  i++
}
 
let reverseWord = ""




for(let val of arr){
	reverseWord = reverseWord + " " +val
}
console.log(reverseWord)