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📜 WAYPOINT LESSON

Checkpoint — Methods

⭐ beginner⏳ 20 min read📍 Lesson 21 of 85

Dispatch, contracts, and counting — two methods, both tested on their edges.

Checkpoint: the operator console

Task: implement two methods:

  1. static double Apply(char op, double a, double b) — +, -, * behave as usual; / divides but throws DivideByZeroException when b is exactly 0 (remember: doubles don't throw on their own — 1.0 / 0.0 is Infinity, so you must check); any other character throws ArgumentException.
  2. static int CountVowels(string s) — count of vowels aeiou, case-insensitive; null or empty input counts 0.