(Count the letters in a string) Rewrite the countLetters function in Programming Exercise...

(Count the letters in a string) Rewrite the countLetters function in Programming Exercise using the string class as follows:

int countLetters(const string& s)

Write a test program that reads a string and displays the number of letters in the string. Sample runs are the same as in Programming Exercise.

Programming Exercise

(Count the letters in a string) Write a function that counts the number of letters in a C-string using the following header:

int countLetters(const char s[])

Write a test program that reads a C-string and displays the number of letters in the string. Here is a sample run of the program: