How can we extend the printRoad() function to print a road with a certain number of segments? The answer is simple. We can let the printRoad() function accept a parameter, called numSegments, to print a certain number of road segments.

The following code snippet shows how that will look:

void printRoad(int numSegments)
{
  // use a for loop to print numSegments road segments
  for( int i = 0; i < numSegments; i++)
  {
    cout << "*   *" << endl;
    cout << "* | *" << endl;
    cout << "* | *" << endl;
    cout << "*   *" << endl;
  }
}

The following screenshot shows the anatomy of a function that accepts an argument:

Call this new version of printRoad(), asking it to print four segments, as follows:

printRoad( 4 );    // function call

The 4 between the brackets of the function call in the preceding statement gets assigned to the numSegments variable of the printRoad(int numSegments) function. This is how the value 4 gets passed to numSegments:

An illustration of how printRoad(4) will assign the value 4 to the numSegments variable

So, numSegments gets assigned the value passed between the brackets in the call to printRoad().