Scope Rules (so far)

• A function name has global scope
• The scope of a formal parameter is identical to the scope of a local variable declared in the function
• The scope of a global variable or constant extends from its declaration to the end of the file
• The scope of a local variable or constant extends from its declaration to the end of the block in which it is declared

const float PI = 3.14f;        // global
float areaOfCircle(float r);   // global

void main(void)
{
  float area;                // local
  area = areaOfCircle(4.5);
	. . .
}

// formal parameters are local to the
// function
float areaOfCircle(float radius)
{
  float area;                // local

  area = PI * radius * radius;

  return area;
}