chapter 9 part 1 foc

• Function


  A rule or correspondence between values, called the function's arguments, and the unique value of the function associated with the arguments
• Types of C++ functions

  • Standard functions
  • User-defined functions
• C++ function structure


  • Function signature
  • Function body
• Declaring and Implementing C++ functions

  1. Sharing data among functions through function parameters

  2. Value parameters
• Function arguments


  Constants, variables or more complex expressions
• Why using functions


  • Divide and conquer
  • Reusability
  • Components
• Predefined functions


  Part of the C++ language, provided in function libraries
• Predefined functions


  • abs(x)
  • sin(x)
  • log(x)
  • pow(x, n)
• Library functions


  Built-in functions that come with the compiler, source code definition does not appear in your program
• Header files for library functions

  • cctype
  • cmath
  • stdlib
  • time
• Library functions work as a black box
• Math functions in cmath

  • abs(x)
  • pow(x,y)
  • pow10(x)
  • sqrt(x)
• Library function examples


  • Calculating area of a circle
  • Calculating square root of sum of two numbers
• More mathematical functions in cmath

  • sin
  • cos
  • tan
  • sqrt
  • log
  • abs