More Math

• When multiple types are involved in a computation
  • 3 + 2.98 will become a float even if 3 is an int
  • The compiler will convert between types.
    • This is called type coercion or just coercion
  • When we do it, it is called type conversion
  • In general it is better if we control things.
• Type conversion
  • There are multiple ways to do this.
  • You will assume float data
  • You will rarely see (int) data
  • You will frequently see int(data)
  • You should probably use static_cast<int>(data)
  • You can cast from any type to most other types.
• A word of caution
  • Conversion and type casting doesn't always produce what you expect.
  • Assume float floatData = 4.6;
  • intData = static_cast<int>(floatData) produces a 4.
  • Conversion to integer truncates, it does not round.
  • A way to round is
  • intData = static_cast<int>(floatData + 0.5) produces a 5.
• Write a program that converts between Fahrenheit and Celsius
  • $c = \frac{5}{9}(f-32)$
  • $f = \frac{9}{5}c + 32$