Conversion Program with Pass by Value and Pass by Reference

[JHernandez860]

Hi, this site has been extremely helpful with my path down learning C++ but I have ran into an issue on one of my assignments. Below is my code I wrote to create a basic program for conversions. My assignment now is to modify the program so that each calculation is performed by a user defined function. At least one of the user defined functions will utilize the "pass by value" method and at least one using the "pass by reference" method.

I am a little confused on how to start this and how it should exactly look like. If anyone could please provide me an example of how I should start, or some basic syntax so I can grasp the concept of how I should do this I would greatly appreciate it!

#include<iostream> //Required for cout
#include<iomanip>

using namespace std;

int main ()
{
    
cout << "Which way would you like to convert?\n" <<endl ;   

char value;
cout << "1. English to Metic" <<endl ;
cout << "2. Metric to English\n" <<endl ;

cout << "Enter Corresponding Number: " ;
cin >> value;


    switch(value) {
                  
    case '1': // Case for English to Metric
            
    int code;
    
    double value, result;
    
    double conv_centimeters(2.54), conv_liters(3.787), conv_newtons(4.448);
    
    cout << "\nWhat would you like to convert?\n";
    cout << "1. Fahrenheit to Celsius " << endl;
    cout << "2. Inches to Centimeters " << endl;
    cout << "3. Gallons to Liters " << endl;
    cout << "4. Pounds Force to Newtons " << endl;
    
    cout << "\nEnter Corresponding Number: ";
    cin >> code;  
    
    cout << "\nEnter the value to convert: ";  
    cin >> value;
                 
    
    
    if(code == 1) {
            
            result = (value-32)*5.0/9.0;
            cout << value << " Degrees Farenheit is equal to " << setprecision(4) << result << " Degrees Celsius\n";
                    
                    
                  }  
    
    if(code == 2) {
            
            result = value*conv_centimeters;
            cout << value << "Inches are equal to " << setprecision(4) << result << " Centimeters\n";
                    
                    
                  } 
    
    if(code == 3) {
            
            result = value*conv_liters;
            cout << value << " Gallons are equal to " << setprecision(4) << result << " Liters\n";
                    
                    
                  }
    
    if(code == 4) {
            
            result = value*conv_newtons;
            cout << value << " Pound Forces are equal to " << setprecision(4) << result << " Newtons\n";
                    
                    
                  }
                  }
                  

  
    switch(value) {
                                  
    case '2': // Case for Metric To English
            
    int code;
    
    double value, result;
    
    const double conv_inches(0.39), conv_gallons(0.26), conv_poundsforce(0.22);
    
    cout << "\nWhat would you like to convert?\n";
    cout << "1. Celsius to Fahrenheit " << endl;
    cout << "2. Centimeters to Inches " << endl;
    cout << "3. Liters to Gallons " << endl;
    cout << "4. Newtons to Pound Forces " << endl;
    
    cout << "\nEnter Corresponding Number: ";
    cin >> code;  
    
    cout << "\nEnter the value to convert: ";  
    cin >> value;
                 
    
    
    if(code == 1) {
            
            result = value*1.8+32;
            cout << value << "  Degrees Celsius is equal to " << setprecision(4) << result << " Degrees Fahrenheit\n";
                    
                    
                  }  
    
    if(code == 2) {
            
            result = value*conv_inches;
            cout << value << " Centimeters are equal to " << setprecision(4) << result << " Inches\n";
                    
                    
                  } 
    
    if(code == 3) {
            
            result = value*conv_gallons;
            cout << value << " Liters are equal to " << setprecision(4) << result << " Gallons\n";
                    
                    
                  }
    
    if(code == 4) {
            
            result = value*conv_poundsforce;
            cout << value << " Newtons are equal to " << setprecision(4) << result << " Pound Forces\n";
                    
                    
                  }
                  }
                  
    cout << "\nConversion complete!! \n" << endl;              
                  
                  
    system ("pause");
    return 0;
    
}