Functions

• We have already seen functions.
• program from chapter 1
• Trace this code.
• int square(int); is the Function Prototype
• Using the function is known as
  • invoking the function
  • calling the function
• We pass parameters through an argument list.
• Value returning functions return a value.
• Void functions - don't return a value.
• Consider the ftoc.cpp before and after .
• We are given a set of standard functions. (From page 121)

• <cstdlib>	abs(i)	int	int
  <cmath>	cos(x)	float	float
  <cmath>	sin(x)	float	float
  <cmath>	fabs(x)	float	float
  <cmath>	pow(x,y)	float	float
  <cmath>	sqrt(x)	float	float

  • sin and cos operate on angles in radians.
  • pow - second argument positive if x=0, x < 0, y must be even.
  • sqrt- x must be non negative.