I have a question regarding to character array in c++

Write a Menu Driven C++ program that creates a character array/string by taking input from user and perform following tasks by displaying menu to user:  Calculate length of string.  Count number of words in string.  Check a string is palindrome or not.  Find a word within the array. If found display its starting position.  Convert a string in lowercase.  Convert a string in uppercase.

This is the question that I have been trying to solve but I can't. I want to get this done by using character rrays but no user defined functions. Thanks