Predefined Functions

• A C++ function is a named, parameterized block of code for accomplishing a useful task.

  • Examples (see Appendix 4, pgs 1003-1010):

    • Arithmetic functions:  abs(), sqrt(), pow(), etc.

    • Character functions:  isdigit(), toupper(), etc.

    • Random number functions:  srand() and rand().

    • Trigonometric functions:  sin(), cos(), tan(), etc.

• Named:  By naming the block of code we can access or "call" it again and again.

• Parameterized:  By providing parameters, or arguments, the function can act on different values to produce different results.

• A predefined function is a function that someone else wrote for us to use.

• To use predefined functions we need to be able to understand function prototypes