Exercise 4.4 (Completed)

1. (Modify) Rewrite the following if-else chain by using a switch statement:
 if (letterGrade == 'A')
   cout << “The numerical grade is between 90 and 100\n”;
 else if (letterGrade == 'B')
   cout << “The numerical grade is between 80 and 89.9\n”;
 else if (letterGrade == 'C')
   cout << “The numerical grade is between 70 and 79.9\n”;
 else if (letterGrade == 'D')
   cout << “How are you going to explain this one?\n”;
 else
 {
   cout << “Of course I had nothing to do with my grade.\n”;
   cout << “It must have been the professor's fault.\n”;
 }
 ---------------------Changed----------------------------------
 switch (letterGrade)
{
  case 'A':
    cout << “The numerical grade is between 90 and 100”;
    break;
  case 'B':
    cout << “The numerical grade is between 80 and 89.9”;
    break;
  case 'C':
    cout << “The numerical grade is between 70 and 79.9”;
    break;
  case 'D':
    cout << “How are you going to explain this one?”;
    break;
  default:
    cout << “Of course I had nothing to do with the grade.”;
    cout << “\nIt must have been the professor's fault.”;
}
2. (Modify) Rewrite the following if-else chain by using a switch statement:
 if (bondType == 1)
 {
   inData();
   check();
 }
 else if (bondType == 2)
 {
    dates();
   leapYr();
 }
 else if (bondType == 3)
 {
   yield();
   maturity();
 }
 else if (bondType == 4)
 {
   price();
   roi();
 }
 else if (bondType == 5)
 {
   files();
   save();
 }
 else if (bondType == 6)
 {
   retrieve();
   screen();
 }
 ----------------------- Switch Version----------------------------
 
 switch (bondType)
{
  case 1:
    inData();
    check();
    break;
  case 2:
    dates();
    leapYr();
    break;
  case 3:
    yield();
    maturity();
    break;
  case 4:
    price();
    roi();
    break;
    case 5:
    files();
    save();
  default:
    retrieve();
    screen();
}

3. (Program) Each storage drive in a shipment is stamped with a code from 1 to 4, indicating
the following storage capacities:
Code  Capacity
1     2 GB
2     4 GB
3    16 GB
4    32 GB
Write, compile, and run a C++ program that accepts the code number as an input value and,
based on the value entered, displays the correct storage drive capacity.

#include <iostream>
using namespace std;
int main(){
switch (code){
case 1: 
cout << 2 <<"GB"<<endl;
case 2:
cout << 4 << "GB" << endl;
case 3:
cout << 16 << "GB" << endl;
case 4:
cout << 32 << "GB" << endl;
default:
cout << "Nothing" << endl;
}
return 0;
}
4. (Modify) Rewrite Program 4.4 by using a switch statement.
#include <iostream>
using namespace std;
int main(){
switch (marcode){
case 'M': 
cout << "Individual is married."<<endl;
case 'S':
cout << "Individual is single" << endl;
default:
cout << "Nothing" << endl;
}
return 0;
}
5. (Modify) Repeat Exercise 9 in Section 4.3, using a switch statement instead of an
if-else chain.
#include <iostream>
using namespace std;
int main(){
double number, Celsius, Fahrenheit;
char letter;
cout << Enter a number and a letter<< endl;
cin >> number >> letter;
Celsius = ((5/9)*(number - 32));
Fahrenheit = ((9.0/5.0) * number + 32.0); 
if ( letter == 'f'){
cout << Celsius << endl;}
else if (letter == 'c'){
cout << Fahrenheit << endl;}
return 0;
}
-------------------Switch Statements-----------------------------------------------
#include <iostream>
using namespace std;
int main(){
double number, Celsius, Fahrenheit;
char letter;
cout << Enter a number and a letter<< endl;
cin >> number >> letter;
Celsius = ((5/9)*(number - 32));
Fahrenheit = ((9.0/5.0) * number + 32.0);
switch (letter){
case 'f': 
cout << Fahrenheit << endl;
case 'c':
cout << Celsius << endl;
}
return 0;
}

6. (Modify) Rewrite Program 4.6 by using a character variable for the select code.

#include <iostream>
using namespace std;
int main()
{
  int opselect;
  double fnum, snum;
  cout << “Please type in two numbers: “;
  cin  >> fnum >> snum;
  cout << “Enter a select code: “;
  cout << “\n        1 for addition”;
  cout << “\n        2 for multiplication”;
  cout << “\n        3 for division : “;
  cin  >> opselect;
  switch (opselect)
  {
    case 'a':
      cout << “The sum of the numbers entered is “ 
           << fnum+snum << endl;
      break;
    case 'b':
      cout << “The product of the numbers entered is “ 
           << fnum*snum << endl;
      break;
    case 'c':
      cout << “The first number divided by the second is “ 
           << fnum/snum << endl;
      break;
  }      // end of switch
  return 0;
}
7. (For thought) Determine why the if-else chain in Program 4.5 can’t be replaced with a
switch statement.

The expression in the switch statement must evaluate to an integer quantity and be tested
for equality. The if-else chain in Program 4.5 compares double-precision values, violating
the switch statement’s requirements for integer relational expressions.