Ruby - twoCounter.txt

Write a function to count all the number of 2s between 0 and n

- - - - - - My Answer - - - - - -

def twoCounter(n)
    counter, numArr = 0, (0..n).to_a
    
    numArr.join('').split('').map { |num| num == "2" ? counter+=1 : nil }
    counter
end

twoCounter(300)
 => 160

twoCounter(13)
 => 2


- initialize a counter and a numArr (with all ints between 0 and n)
- use ‘.join’ and then ‘.split’
  - this joins all the ints as a string
  - then splits the string into individual chars
- map over this and look for ‘2’. increment the counter for each instance.