Given a simple implementation of string calculator, how would you refactor this, based on SOLID principles?

1. Create a simple String calculator with a method int Add(string numbers)
2. The method can take 0, 1 or N numbers, and will return their sum (for an empty string it will return 0) for example “” or “1” or “1,2” or “1,2,3,4,5”
3. Allow the Add method to handle an unknown amount of numbers
4. Calling Add with a negative number will throw an exception “negatives not allowed”
5. Numbers bigger than 1000 should be ignored, so adding 2 + 1001 = 2

Given a simple implementation of string calculator.

Refactor string calculator based in SOLID Principles.

All Test must pass

The code should be flexible for receive different separators or validations on the future

• Jorge Sánchez Fernández aka xurxodev

Copyright 2016 Jorge Sánchez Fernández

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