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Cesar Del rio
Cesar Del rio

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#6 - Incrementer CodeWars Kata (7 kyu)


Given an input of an array of digits, return the array with each digit incremented by its position in the array: the first digit will be incremented by 1, the second digit by 2, etc. Make sure to start counting your positions from 1 ( and not 0 ).

Your result can only contain single digit numbers, so if adding a digit with its position gives you a multiple-digit number, only the last digit of the number should be returned.

return an empty array if your array is empty
arrays will only contain numbers so don't worry about checking that


[1, 2, 3] --> [2, 4, 6] # [1+1, 2+2, 3+3]
[4, 6, 9, 1, 3] --> [5, 8, 2, 5, 8] # [4+1, 6+2, 9+3, 1+4, 3+5]
# 9+3 = 12 --> 2

My solution:

function incrementer(nums) { 
  if(nums == []) return[]
  return,i)=> (i + n + 1)%10)

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I started with a conditional, if the array is empty it'll return an empty array, if not it'll return the result, for the result I mapped the nums input, taking each number and its index as parameters, then I summed the index + number + 1, I summed one because I have to start counting the postions from 1, so every index needs to be summed one, then to that result I used the % operator so it returns only the remainder of the division and I can get only the second digit of the result because it is divided by 10

Comment how would you solve this kata and why? 👇🤔

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