### Answers to string exercises (using for and range)

Main point: you can use helper functions (in particular, we use the findLetter() function a lot here) if you include that helper function in the CodingBat window.

```# CodingBat homework

# ---------------------------------
def countLetter(string,letter):
count = 0
for i in range(len(string)):
if string[i] == letter:
count += 1
return count
# ----------------------------------
# we can use the helper function findLetter() here, so
# we just define it below countVowels()

def countVowels(s):
vowels = 'aeiouAEIOU'
count = 0
for i in range(len(s)):
if findLetter(vowels,s[i]) >= 0:
count += 1
return count

def findLetter(string,letter):
for i in range(len(string)):
if string[i] == letter:
return i
return -1

# ------------------------------------
def isConsonant(c):
lower = 'abcdefghijklmnopqrstuvwxyz'
upper = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
vowels = 'aeiouAEIOU'
# test if the character is a letter:
if findLetter(lower,c) >= 0 or findLetter(upper,c) >= 0:
# and if so, is it not a vowel?
if findLetter(vowels,c) < 0:
return True
return False

# ---------------------------------------
def countWord(original,word):
ln = len(word)
count = 0
for i in range(len(original)):
if original[i:i+ln] == word:
count += 1
return count

# ---------------------------------
def noVowels(s):