Overload function template printArray of Fig. 14.1 so that it takes two additional integer arguments, namely int lowSubscript and int highSubscript. A call to this function will print only the designated portion of the array. Validate lowSubscript and highSubscript; if either is out of range or if highSubscript is less than or equal to lowSubscript, the overloaded printArray function should

Question

return 0; otherwise, printArray should return the number of elements printed. Then modify main to exercise both versions of printArray on arrays a, b and c (lines 23–25 of Fig. 14.1). Be sure to test all capabilities of both versions of printArray.

What will be an ideal response?

Answer 1

```
// Using template functions
#include
using namespace std;

// function template printArray definition
// original function from Fig. 14.1
template< typename T >
void printArray( const T *array, int count )
{
// display array
for ( int i = 0; i < count; i++ )
cout << array[ i ] << " ";

cout << endl;
} // end function printArray

// overloaded function template printArray
// takes upper and lower subscripts to print
template< typename T >
int printArray( T const * array, int size, int lowSubscript,
int highSubscript )
{
// check if subscript is negative or out of range
if ( size < 0 || lowSubscript < 0 || highSubscript >= size )
return 0;

int count = 0;

// display array
for ( int i = lowSubscript; i <= highSubscript; i++ )
{
count++;
cout << array[ i ] << ' ';
} // end for

cout << endl;
return count; // number of elements output
} // end overloaded function printArray

int main()
{
const int ACOUNT = 5; // size of array a
const int BCOUNT = 7; // size of array b
const int CCOUNT = 6; // size of array c

// declare and initialize arrays
int a[ ACOUNT ] = { 1, 2, 3, 4, 5 };
double b[ BCOUNT ] = { 1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7 };
char c[ CCOUNT ] = "HELLO"; // 6th position for null
int elements;

// display array a using original printArray function
cout << "\nUsing original printArray function\n";
printArray( a, ACOUNT );

// display array a using new printArray function
cout << "Array a contains:\n";
elements = printArray( a, ACOUNT, 0, ACOUNT - 1 );
cout << elements << " elements were output\n";

// display elements 1-3 of array a
cout << "Array a from positions 1 to 3 is:\n";
elements = printArray( a, ACOUNT, 1, 3 );
cout << elements << " elements were output\n";

// try to print an invalid element
cout << "Array a output with invalid subscripts:\n";
elements = printArray( a, ACOUNT, -1, 10 );
cout << elements << " elements were output\n\n";

// display array b using original printArray function
cout << "\nUsing original printArray function\n";
printArray( b, BCOUNT );

// display array b using new printArray function
cout << "Array b contains:\n";
elements = printArray( b, BCOUNT, 0, BCOUNT - 1 );
cout << elements << " elements were output\n";

// display elements 1-3 of array b
cout << "Array b from positions 1 to 3 is:\n";
elements = printArray( b, BCOUNT, 1, 3 );
cout << elements << " elements were output\n";

// try to print an invalid element
cout << "Array b output with invalid subscripts:\n";
elements = printArray( b, BCOUNT, -1, 10 );
cout << elements << " elements were output\n\n";

// display array c using original printArray function
cout << "\nUsing original printArray function\n";
printArray( c, CCOUNT );

// display array c using new printArray function
cout << "Array c contains:\n";
elements = printArray( c, CCOUNT, 0, CCOUNT - 2 );
cout << elements << " elements were output\n";

// display elements 1-3 of array c
cout << "Array c from positions 1 to 3 is:\n";
elements = printArray( c, CCOUNT, 1, 3 );
cout << elements << " elements were output\n";

// try to display an invalid element
cout << "Array c output with invalid subscripts:\n";
elements = printArray( c, CCOUNT, -1, 10 );
cout << elements << " elements were output" << endl;
} // end main
```
Using original printArray function
1 2 3 4 5
Array a contains:
1 2 3 4 5
5 elements were output
Array a from positions 1 to 3 is:
2 3 4
3 elements were output
Array a output with invalid subscripts:
0 elements were output
Using original printArray function
1.1 2.2 3.3 4.4 5.5 6.6 7.7
Array b contains:
1.1 2.2 3.3 4.4 5.5 6.6 7.7
7 elements were output
Array b from positions 1 to 3 is:
2.2 3.3 4.4
3 elements were output
Array b output with invalid subscripts:
0 elements were output
Using original printArray function
H E L L O
Array c contains:
H E L L O
5 elements were output
Array c from positions 1 to 3 is:
E L L
3 elements were output
Array c output with invalid subscripts:
0 elements were output