C++ solution

I tried to keep it simple, but I am open to suggestions if someone sees a simpler solution.

<pre><code>

include <iostream>

include <string>

// Assign a number for letters A-Z as 1-26, respectively. int numberEquivalent(char character) {

int returnedValue = 0;
char lowerChar = tolower(character);

//Using ASCII, drop to lower case & check for values 96 - 122 (a through z)
if(int(lowerChar) > 95 && int(lowerChar) < 123)
    returnedValue = int(lowerChar) - 96;
else
    returnedValue = 0;

return returnedValue;

} </code></pre>

<pre><code> // Add together the assigned numbers together. int letterSum(std::string letter) {

int evaluation=0; //    The holder for the final sum of numbered letters.

for (int counter{ 0 }; counter < letter.length(); counter++) {
    evaluation = evaluation + numberEquivalent(letter[counter]);
}
return evaluation;

} </code></pre>

<pre><code> int main() { std::cout << "Please enter a word: "; // Both words and sentences work std::string sentence{}; std::getline(std::cin >> std::ws, sentence);

int sumOfAllLetters{ letterSum(sentence) };

std::cout << "The sum of each letter in " << sentence << " equals " << sumOfAllLetters << '\n';

} </code></pre>