Write a menu based program in functions to calculate string length string compare string reverse string substring string concatenation?

Answer 1

#include<iostream> #include<string> #include<sstream> #include<vector> #include<conio.h> // required by getch() std::string input_string (std::string prompt) { while (true) { std::string input; std::cout << prompt; std::getline (std::cin, input); if (input.size()) return input; std::cout << "Invalid input. Empty strings are not permitted.\n"; } } size_t input_unsigned (std::string prompt) { while (true) { std::string input = input_string (prompt); std::stringstream ss; ss << input; size_t s; if (ss>>s && s) return s; std::cout << "Invalid input. Values must be non-zero.\n"; } } void string_length() { std::string str = input_string ("Enter the string you wish to know the length of:\n"); std::cout << "The string is " << str.size() << " characters long.\n" << std::endl; } void string_compare() { std::pair<std::string, std::string> strings; strings.first = input_string ("Enter the first string you wish to compare:\n"); strings.second = input_string ("Enter the second string you wish to compare:\n"); int compare = strings.first.compare (strings.second); std::cout << "The result of the camprison is: " << compare << '\n' << std::endl; } void string_reverse() { std::string str = input_string ("Enter the string you wish to reverse:\n"); for (size_t f=0, r=str.size()-1; f<r; ++f, --r) { char t = str[f]; str[f] = str[r]; str[r] = t; } std::cout << "The reversed string is:\n" << str << '\n' << std::endl; } void string_substring() { std::string str = input_string ("Enter a string:\n"); size_t pos = input_unsigned ("Enter the offset of the substring:\n"); size_t len = input_unsigned ("Enter the length of the substring:\n"); std::cout << "The substring is: " << str.substr(pos,len) << '\n' << std::endl; } void string_concatenation() { std::pair<std::string, std::string> strings; strings.first = input_string ("Enter the first string you wish to concatenate:\n"); strings.second = input_string ("Enter the second string you wish to concatenate:\n"); std::string concat = strings.first + strings.second; std::cout << "The result of the concatenation is: " << concat << '\n' << std::endl; } int main() { while (true) { std::cout << "MAIN MENU\n"; std::cout << "=========\n" << std::endl; std::cout << "1 - String length\n"; std::cout << "2 - String compare\n"; std::cout << "3 - String reverse\n"; std::cout << "4 - String substring\n"; std::cout << "5 - String concatenation\n"; std::cout << "X - Exit program\n"; #pragma warning(disable : 4996) switch ((char) getch()) { case ('1'): string_length(); break; case ('2'): string_compare(); break; case ('3'): string_reverse(); break; case ('4'): string_substring(); break; case ('5'): string_concatenation(); break; case ('x'): case ('X'): return 0; } } }