Floating Point Continued

• Exercise: Fahrenheit to Celsius
  • C = 5/9(F-32)
  • Why the parenthesis?, What happens without them?
  • My code is here. NOTE: THIS CODE USES STUFF WE TALK ABOUT LATER. IT IS A FINAL EXAMPLE OF THE CODE, NOT THE WORK IN CLASS
• Coercion : Automatic conversion
  • Bad deal
  • FLOAT -> INT (drop the decimal part)
  • int = float + 0.5 does rounding for us.
  • INT -> FLOAT (add a .0)
  • Single type expressions are evaluated in the type of the expression and then cast.
  • A Mixed Type Expression has multiple types, and all operators are converted to float, the operation is performed and the result is a float.
  • Some code examples.
• Casting: programmer conversion
  • It is better if you convert yourself
  • two styles:
    • float (var or expression)
    • (float) var or expression
• Output manipulators
  • You know about endl
  • setw(n)
    • #include <iomanip>
    • Sets the width of numeric and string output.
    • Is a mininal width suggestion. (things will take up more space if they need to)
    • Only good for the next variable output.
  • setprecision(n)
    • For the life of the program, or until another setprecision is called.
    • Digits to the right of the decimal place.
  • showpoint
    • Always show the decimal point in floating point numbers
    • We need cout.setf(ios::showpoint);
  • fixed
    • Dont print in scientific notation.
    • We need to use cout.setf(ios::fixed, ios::floatfield);