Building Calculator

This project will solidify the use of functions. We will build a simple calculator. The project is simple, and by now, you're expected to know all of the basic steps of creating a project, so we won't expand much on those. Into coding we dive!

Assignment

1. Create github repo, clone it, create necessary files.
2. Your calculator must have at least 4 functionalities: addition, substraction, multiplication, and division.
3. Make the main wrapper function that will take user's input (format: [integer] [operation sign] [integer]). Break the input string into the number arguments and the operation sign, invoke the corresponding function based on the provided operation sign, and pass the numbers as parameters. (Hint: use the switch statement.) Don't forget to convert the numbers input into integers!
4. (Extra-credit!) Our simple calculator is pretty much done. However, there are some (unnecessary) things to make it slightly better. For example, implement the while loop to make the function run indefinitely (until the user quits with ctrl-c).
5. (Extra-credit!) Now, user's input can be unpredictable, and if it's not an integer, our program will crash. We don't want it, so let's fix it! Implement checks for whether that input is a number (after conversion) and print the corresponding error message if it's not.
6. (Extra-extra-credit!) Implement ability for user to input more than one operation.