coding for food

[Ruby] Last Index

silveryen 2022. 8. 6. 10:25

Write a method last_index that takes in a string and a character. The method should return the last index where the character can be found in the string.

def last_index(str, char)

end

puts last_index("abca", "a")       #=> 3
puts last_index("mississipi", "i") #=> 9
puts last_index("octagon", "o")    #=> 5
puts last_index("programming", "m")#=> 7
# my code

def last_index(str, char)
  word = str.split("")
  updateidx = 0
  word.each.with_index do |spell, idx|
    if spell == char
      updateidx = idx
    end
  end

  return updateidx
end

puts last_index("abca", "a")       #=> 3
puts last_index("mississipi", "i") #=> 9
puts last_index("octagon", "o")    #=> 5
puts last_index("programming", "m")#=> 7
# solution

def last_index(str, char)
  i = str.length - 1
  while i >= 0
    if str[i] == char
      return i
    end
    i -= 1
  end
end

puts last_index("abca", "a")       #=> 3
puts last_index("mississipi", "i") #=> 9
puts last_index("octagon", "o")    #=> 5
puts last_index("programming", "m")#=> 7