Help with filework and parameter passing!
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Hello everyone. Hoping someone can help me with a some code I am writing for school. I am brand new to C++ and trying code a program that emulates a calculator. This program uses a output file and passes parameter to the two simple functions I have written. I am not sure if I am on the right track here so if someone could take a look and let me know if I am doing this the right way. Thanks in advace.
Dave
/********************************************************************************************************
Purpose: This program simulates a hand-held electronic calculator. The calculator has two registers,
r1 and r2, and an accumulator. The calculator can perform the following mathematical functions:
addition, subtraction, multiplication, division, exponentation, square root.
Error
Checking: This program will check for incorrect menu selection and square root of a negative number
This program also checks for division by zero.
Compiler: Dev-C++ ver 4.9.5.0 Blooshed Software
Limitations: Program is limited to a the given mathematical operands and can only work with to registers or
numbers at once.
*******************************************************************************************************/
#include <iostream.h> // preprocessor directive
#include <iomanip.h> // preprocessor directive
#include <stdlib.h> // preprocessor directive
#include <ctype.h> // preprocessor directive
#include <math.h> // preprocessor directive
#include <fstream.h> // for output file
float Calculator (char operand, float r1, float r2, float answer, ofstream OutAccumulator); // Prototyping of function
void PrintOutput (ofstream OutAccumulator); // Prototyping of function
int main() // function main
{
int stop; // simple stop
char operand;
float r1; // assign decimal value to variable // assign double decimal value to variable
float r2; // assign decimal value to variable
float answer;
char cont ='x'; // setting flag
ofstream OutAccumulator; // holds solution values for problem
cout << "David W. Skurda CMIS140: Assignment #4 11/03/02" << endl;
do // do loop
{
cont = 'x'; // flag
system("cls");
cout.precision(3); // set decimal precision
cout.setf(ios::fixed,ios::floatfield); // set up floating point
cout.setf(ios::showpoint); // output format
OutAccumulator.open("OutAccumulator.dat"); // open file
cout << "--------------------------------------------------------------------------------" << endl;
cout << "| WELCOME TO DAVE'S MATH MACHINE |" << endl;
cout << "| |" << endl;
cout << "| This program simulates a hand-calculator and |" << endl;
cout << "| can perfor the following mathematical operands: |" << endl;
cout << "| Addition = + |" << endl;
cout << "| Subtraction = - |" << endl;
cout << "| Multiplication = * |" << endl;
cout << "| Division = / |" << endl;
cout << "| Exponent = e or E |" << endl;
cout << "| Square Root = s or S |" << endl;
cout << "| To quit type: q or Q |" << endl;
cout << "| |" << endl;
cout << "| Please enter all problems in the folling form: |" << endl;
cout << "| operand, r1, r2 |" << endl;
cout << "| Sample Problem: |" << endl;
cout << "| operand = + |" << endl;
cout << "| r1=2 |" << endl;
cout << "| r2=2 |" << endl;
cout << "| r1+r2=4 |" << endl;
cout << "| |" << endl;
cout << "| NOTE: If you are using the square root operand, |" << endl;
cout << "| enter a 0 for r1 and the number you wish |" << endl;
cout << "| to find the root of for r2. |" << endl;
cout << "| |" << endl;
cout << "--------------------------------------------------------------------------------" << endl;
cout << "Enter the operand to be perfomed."<< endl;
cout << "select one of the following +,-,*,/,e,s, or q: ";
cin >> operand;
cout << "Enter the first number to be used in the probem 'r1'."<< endl;
cout << "r1: ";
cin >> r1;
cout << "Enter the second number to be used in the problem 'r2'."<< endl;
cout << "r2: ";
cin >> r2;
cout << "You entered:" << r1 << operand << r2 << endl;
float Calculator (char operand, float r1, float r2, float answer, ofstream OutAccumulator); // function call for Calculator
void PrintOutput (ofstream OutAccumulator); // function call for Printoutput
while((cont != 'Y') && (cont != 'N')) // prompt user to repeat or close program
{ // while loop
cout << " Do you want to solve another problem? (Y/N): ";
cin >> cont;
cont = toupper(cont);
if((cont != 'Y') && (cont != 'N'))
{
cout << " Enter 'Y' for yes or 'N' for no. \n"; // cout statement outputs a character string
}
}
}while((cont != 'N')); // while loop
cout << " Type any key and then enter to end program."; // simple stop added to the program
cin >> stop; // so the output is viewable in dos
return 0; // end function
}
}
float Calculator (char operand, float r1, float r2, float answer, ofstream OutAccumulator);
{
switch (operand) // switch statement to chose proper operand
{
case '+' : answer = ( r1 + r2);
case '-' : answer = ( r1 - r2);
case '*' : answer = ( r1 * r2);
case '/' : answer = ( r1 / r2);
if( r2 == 0 ) // error checking for dision by zero
{ // if loop
cout << " Division by zero is not allowed. \n\n"<< endl; // cout statement outputs a character string
}
case 'E' : answer = pow(r1, r2);
case 'S' : answer = sqrt(r2);
if( r1 == -float ); // error checking for square root of a negative number
{ // if loop
cout << " Square root of a negative number is not allowed. \n\n"<< endl; // cout statement outputs a character string
}
case 'Q' : return 0;
default : cout << " You have entered an invalid menu selection. Please enter an operand from the menu above. \n"; // error checking for invalid menu selection // cout statement outputs a character string
}
}
void PrintOutput (ofstream OutAccumulator,float answer)
{
OutAccumulator << "The answer is"<< answer << endl; // print output from file
}
I got boared for 5 min so I fixed your code. You will need to read up on Functions and Switch case. I made comments on all of my changes. Then that way you can tell where they are, and try to determine why they needed to happen. I you get compleatly stuck, then you can contact me by
MSN - curtis8@hotmail.com
ICQ - 82286030
Yahoo! - Curtis8ca
AIM - csutter2
here is the code now
--------------------------------------------------------------------------
#include <iostream.h> // preprocessor directive
#include <iomanip.h> // preprocessor directive
#include <stdlib.h> // preprocessor directive
#include <ctype.h> // preprocessor directive
#include <math.h> // preprocessor directive
#include <fstream.h> // for output file
float Calculator (char operand, float r1, float r2); // Prototyping of function
void PrintOutput (float Answer); // Prototyping of function
int main() // function main
{
//int stop; // simple stop
char operand;
float r1; // assign decimal value to variable // assign double decimal value to variable
float r2; // assign decimal value to variable
float answer;
char cont ='x'; // setting flag
ofstream OutAccumulator; // holds solution values for problem
cout << "David W. Skurda CMIS140: Assignment #4 11/03/02" << endl;
do // do loop
{
cont = 'x'; // flag
system("cls");
cout.precision(3); // set decimal precision
cout.setf(ios::fixed,ios::floatfield); // set up floating point
cout.setf(ios::showpoint); // output format
OutAccumulator.open("OutAccumulator.dat"); // open file
cout << "--------------------------------------------------------------------------------" << endl;
cout << "| WELCOME TO DAVE'S MATH MACHINE |" << endl;
cout << "| |" << endl;
cout << "| This program simulates a hand-calculator and |" << endl;
cout << "| can perfor the following mathematical operands: |" << endl;
cout << "| Addition = + |" << endl;
cout << "| Subtraction = - |" << endl;
cout << "| Multiplication = * |" << endl;
cout << "| Division = / |" << endl;
cout << "| Exponent = e or E |" << endl;
cout << "| Square Root = s or S |" << endl;
cout << "| To quit type: q or Q |" << endl;
cout << "| |" << endl;
cout << "| Please enter all problems in the folling form: |" << endl;
cout << "| operand, r1, r2 |" << endl;
cout << "| Sample Problem: |" << endl;
cout << "| operand = + |" << endl;
cout << "| r1=2 |" << endl;
cout << "| r2=2 |" << endl;
cout << "| r1+r2=4 |" << endl;
cout << "| |" << endl;
cout << "| NOTE: If you are using the square root operand, |" << endl;
cout << "| enter a 0 for r1 and the number you wish |" << endl;
cout << "| to find the root of for r2. |" << endl;
cout << "| |" << endl;
cout << "--------------------------------------------------------------------------------" << endl;
cout << "Enter the operand to be perfomed."<< endl;
cout << "select one of the following +,-,*,/,e,s, or q: ";
cin >> operand;
cout << "Enter the first number to be used in the probem 'r1'."<< endl;
cout << "r1: ";
cin >> r1;
cout << "Enter the second number to be used in the problem 'r2'."<< endl;
cout << "r2: ";
cin >> r2;
cout << "You entered:" << r1 << operand << r2 << endl;
answer = Calculator (operand, r1, r2); // function call for Calculator
PrintOutput (answer); // function call for Printoutput
while((cont != 'Y') && (cont != 'N')) // prompt user to repeat or close program
{ // while loop
cout << " Do you want to solve another problem? (Y/N): ";
cin >> cont;
cont = toupper(cont);
if((cont != 'Y') && (cont != 'N'))
{
cout << " Enter 'Y' for yes or 'N' for no. \n"; // cout statement outputs a character string
}
}
}while((cont != 'N')); // while loop
//cout << " Type any key and then enter to end program."; // simple stop added to the program
//cin >> stop; // so the output is viewable in dos
system("PAUSE");
return 0; // end function
}
//} Removed unnessiary brace
float Calculator (char operand, float r1, float r2)
{
float answer;//added
switch (operand) // switch statement to chose proper operand
{
case '+' : answer = ( r1 + r2);
break;//added all breaks and fixed error checking
case '-' : answer = ( r1 - r2);
break;
case '*' : answer = ( r1 * r2);
break;
case '/' :
if( r2 == 0 ) // error checking for dision by zero
{ // if loop
cout << " Division by zero is not allowed. \n\n"<< endl; // cout statement outputs a character string
break;
}
answer = ( r1 / r2);
break;
case 'e'://added
case 'E' : answer = pow(r1, r2);
break;
case 'S' :
case 's': //added
if( r1 < 0 ); // error checking for square root of a negative number //fixed -float
{ // if loop
cout << " Square root of a negative number is not allowed. \n\n"<< endl; // cout statement outputs a character string
break;
}
answer = sqrt(r2);
break;
case 'q'://added
case 'Q' : return 0;
break;
default : cout << " You have entered an invalid menu selection. Please enter an operand from the menu above. \n"; // error checking for invalid menu selection // cout statement outputs a character string
break;
}
return answer;//added
}
void PrintOutput (float answer) //fixed answer output
{
cout << "The answer is"<< answer << endl; // print output from file
}
--------------------------------------------------------------------------
This code brought to you by...
Curtis ;)
Thanks much appreciated!
Dave
One thing you can do, when you have a long bunch of code in which you are making changes that someone might want to find and look at, is to put a key in your comments. My initials are WAK, so that is usually what I will use, i.e.
} //WAK - Remove unneccessary brace
Then they, or I, can do a search and find what I changed. Habit I go into when working with others, take it or leave it as sound advice...
Wayne
One more quick question!
In the beginning of the main I open a file. I want to send the answer to file and then close the file out.
OutAccumulator.open("OutAccumulator.dat");
OutAccumulator >> float answer >> endl;
OutAccumulator.close("OutAccumulator.dat");
Where do I need to implement this? Thanks in advance.
Dave
Thanks Wayne I will keep that in mind.
Dave - you are trying to use files? Why would you save the answer to a file? Oh well here you go...
//need
#include <fstream.h>
//in main
ofstream OutAccumulator ("OutAccumulator.dat");
//after you have answer
OutAccumulator >> answer >> endl;
//before end of main
OutAccumulator.close();
Hope this helps
Curtis