C / C++ / MFC

#ifndef _MYCODE_
#define _MYCODE_

// Place public defines, structures  etc here .. random couple of sample defines as example
#define DEV_OK			0	// No device error
#define DEV_ERROR       -1	// Device access error

// Some prototype functions I will define in the main body file
void MyFunction1 (int someValue);
int MyFunction2 (void);

#endif 

#include "mycode.h"  // Include your own header file

// Private internal stuff not visible outside the unit because its not in .H file

// An private integer which will just hold our function value
int CurrentValue = 0;

// Our prototype functions now get code

void MyFunction1 (int someValue){
   CurrentValue = someValue;    // Lets just hold value passed in
}

int MyFunction2 (void){
   return (currentValue);       // Just return current value
}

#ifndef _CALCULATION_H
#define _CALCULATION_H
#include "calculation.cpp"
#include "getinput.cpp"

void input_Func(void); //Input function of text.
void input_Area(void); //Input function of Area.
void input_Trap(void); //Input function of Trapezoid.
float rectangle_Area (float , float); //Declaration for Rectangle Area.
float trapezoid_Area (float , float, float); //Declaration for Trapezoid Area.

#endif

#include "calculation.h"

//Calculation of Rectangle Area.
float rectangleArea (float width, float length)
{
    float Area_Rectange = 0;
    Area_Rectange = width * length;
    return (Area_Rectange);
}

//Calculation of Trapezoid Area.
float trapezoidArea (float base1, float base2, float height)
{
    float Area_Trapezoid = 0;
    Area_Trapezoid = ((base1 + base2)/2) * height;
    return (Area_Trapezoid);
}

#include "calculation.h"

//Dealing with the input and output of data
void input_Func(void)
{
    cout << "\n\nEnter 1 to calculate the area of Rectangle" << endl;
    cout << "Enter 2 to calculate the area of a Trapezoid" << endl;
    cout << "\n\nEnter your choice : ";
    cin >> choice;
}

    //Dealing with input of Rectangle
    float input_Area(void)
    {
        float width = 0, length = 0, answer = 0;
        cout << "Enter the width of rectangle :";
        cin >> width;
        cout << "Enter the length of rectangle :";
        cin >> length;
        answer = rectangleArea(width, length);
        cout << "The area of Rectangle is : " << answer << endl;
        break;
    }

        //Dealing with input of Trapezoid.
        float input_Trap(void)
        {
            float base1 = 0, base2 = 0, height = 0, answer = 0;
            cout << "Enter base1 of trapezoid : ";
            cin >> base1;
            cout << "Enter base2 of trapezoid : ";
            cin >> base2;
            cout << "Enter the height of trapezoid : ";
            cin >> height;
            answer  = trapezoidArea(base1, base2, height);
            cout << "The area of Trapezoid is : " << answer << endl;
            break;
        }

/*
-------------------------
Name = Syed Sibt E Hassan
Registration Number = MC160201226
-------------------------
1) Input from the user
2) Function Calls
3) Exit when press 'N'
*/

#include <iostream>
#include "calculation.h"

using namespace std;

int main()
{
    int choice = 0;
    char tryagain = 0;
    do
            input_Func();

            switch(choice)
            {
            case 1:
                {
                    input_Area(); //Get Input of values for Rectangle
                    rectangle_Area (float , float);
                }
            case 2:
                {
                    input_Trap(); //Get Input of Values for Trapezoid
                    trapezoid_Area(float, float, float);
                }
            default:{
                cout << "Neither 1 nor 2 entered." << endl;
                }
            }

            cout << "Do you want to do another calculation? : ";
            cin >> tryagain;
        }while (tryagain == 'Y' || tryagain == 'y');

    return 0;
}

#ifndef _CALCULATION_H
#define _CALCULATION_H
#include "calculation.cpp"
#include "getinput.cpp"
// ...

• One named calculation.h with the declarations for the calculation.c source file
• One named getinput.h with the declarations for the getinput.c source file
• Optionally one named according to your project name with global declarations used by multiple source files and public declarations for your main.c source file

#ifndef _CALCULATION_H
#define _CALCULATION_H

void input_Func(void); //Input function of text.
void input_Area(void); //Input function of Area.
void input_Trap(void); //Input function of Trapezoid.
float rectangle_Area (float , float); //Declaration for Rectangle Area.
float trapezoid_Area (float , float, float); //Declaration for Trapezoid Area.

#endif

#include "calculation.h"   // include you header file 

//Calculation of Rectangle Area.
float rectangleArea (float width, float length)
{
    float Area_Rectange = 0;
    Area_Rectange = width * length;
    return (Area_Rectange);
}
 
//Calculation of Trapezoid Area.
float trapezoidArea (float base1, float base2, float height)
{
    float Area_Trapezoid = 0;
    Area_Trapezoid = ((base1 + base2)/2) * height;
    return (Area_Trapezoid);
}

//Dealing with the input and output of data
void input_Func(void)
{
    cout << "\n\nEnter 1 to calculate the area of Rectangle" << endl;
    cout << "Enter 2 to calculate the area of a Trapezoid" << endl;
    cout << "\n\nEnter your choice : ";
    cin >> choice;
}

// YOU HAVE SERIOUS ERRORS IN THE TWO FUNCTION CODES BELOW

//Dealing with input of Rectangle
float input_Area(void)  // *** ERROR *** YOUR HEADER HEADER FILE IS ==== > void input_Area(void);  WHICH IS IT THEY MUST MATCH??????
{
   float width = 0, length = 0, answer = 0;
   cout << "Enter the width of rectangle :";
   cin >> width;
   cout << "Enter the length of rectangle :";
   cin >> length;
   answer = rectangleArea(width, length);
   cout << "The area of Rectangle is : " << answer << endl;

   
   break;  // <<==== ***** ERROR ***** WHAT ARE YOU BREAKING FROM
   
   /// ***** ERROR *****
   // There is another problem here you have not returned anything 
   // You declare you are going to return a float and don't ..  You put this === > float input_Area(void)
   //
   // I think you may want to return the variable Answer but your code matches
   // the header file returning nothing so I am confused what you are doing
   //
   // You need to be clear are you returning a float or not and fix it
}
 
//Dealing with input of Trapezoid.
float input_Trap(void)    // *** ERROR *** YOUR HEADER HEADER FILE IS ==== > void input_Trap(void);  WHICH IS IT THEY MUST MATCH ??????
{
   float base1 = 0, base2 = 0, height = 0, answer = 0;
   cout << "Enter base1 of trapezoid : ";
   cin >> base1;
   cout << "Enter base2 of trapezoid : ";
   cin >> base2;
   cout << "Enter the height of trapezoid : ";
   cin >> height;
   answer  = trapezoidArea(base1, base2, height);
   cout << "The area of Trapezoid is : " << answer << endl;
   
   break;  // <<==== ***** ERROR ***** WHAT ARE YOU BREAKING FROM
   
   /// ***** ERROR *****
   // There is another problem here you have not returned anything
   // You declare you are going to return a float and don't .. You put this === > float input_Trap(void)
   //
   // I think you may want to return the variable Answer but your code matches
   // the header file returning nothing so I am confused what you are doing
   //
   // You need to be clear are you returning a float or not and fix it
}

Hassan Syed1 wrote:

When I write whole code in main it works well as soon as put the code in separate files I started getting error.

void input_Area(void); //Input function of Area.

float input_Area(void){

float input_Area(void); //Input function of Area.

void input_Area(void){

float rectangleArea (float width, float length)  // * PT1 ... HERE YOU DECLARE YOU ARE RETURNING A FLOAT .. the first word is FLOAT not VOID 
{
    float Area_Rectange = 0;
    Area_Rectange = width * length;
    return (Area_Rectange);  // *** HERE YOU RETURN A FLOAT ... which is exactly what you said at PT1 ... HENCE THIS CODE IS CORRECT
}

/*
-------------------------
Name = Syed Sibt E Hassan
Registration Number = MC160201226
-------------------------
1) Input from the user
2) Function Calls to reactangle and trapezoid
3) Exit loop when input is not 'Y' || 'y'
*/

#include <iostream>
using namespace std;

float rectangleArea (float , float); //Declaration for Rectangle Area
float trapezoidArea (float , float, float); //Declaration for Trapezoid Area.

int main()
{
    int choice = 0;
    char tryagain = 0;
    do
      {
        cout << "\n\nEnter 1 to calculate the area of Rectangle" << endl;
        cout << "Enter 2 to calculate the area of a Trapezoid" << endl;
        cout << "\n\nEnter your choice : ";
        cin >> choice;
            switch(choice)
            {
                         //Dealing with area of Rectangle.
            case 1:
                {

                    float width = 0.0, length = 0.0, answer = 0.0;
                    cout << "Enter the width of rectangle :";
                    cin >> width;
                    cout << "Enter the length of rectangle :";
                    cin >> length;
                    answer = rectangleArea(width, length); //Function Call to Rectangle
                    cout << "The area of Rectangle is : " << answer << endl;
                    break;
                }

                         //Dealing with area of Trapezoid.
            case 2:
                {

                    float base1 = 0.0, base2 = 0.0, height = 0.0, answer = 0.0;
                    cout << "Enter base1 of trapezoid : ";
                    cin >> base1;
                    cout << "Enter base2 of trapezoid : ";
                    cin >> base2;
                    cout << "Enter the height of trapezoid : ";
                    cin >> height;
                    answer  = trapezoidArea(base1, base2, height); //Function Call to Trapezoid
                    cout << "The area of Trapezoid is : " << answer << endl;
                    break;
                }

            default:{
                cout << "Neither 1 nor 2 entered." << endl;
                }
            }

            cout << "\n Do you want to do another calculation? : ";
            cin >> tryagain;
        }while (tryagain == 'Y' || tryagain == 'y');

    return 0;
}

//Calculation of Rectangle Area.
float rectangleArea (float width, float length)
{
    float Area_Rectange = 0.0;
    Area_Rectange = width * length;
    return (Area_Rectange);
}

//Calculation of Trapezoid Area.
float trapezoidArea (float base1, float base2, float height)
{
    float Area_Trapezoid = 0.0;
    Area_Trapezoid = height * (base1 + base2)/2;
    return (Area_Trapezoid);
}

void input_Area(void)  // ** Pt1 here you declare you are going to return nothing AKA a void
{
   float width = 0, length = 0, answer = 0;
   cout << "Enter the width of rectangle :";
   cin >> width;
   cout << "Enter the length of rectangle :";
   cin >> length;
   answer = rectangleArea(width, length);
   cout << "The area of Rectangle is : " << answer << endl;
}

#ifndef _CALCULATION_H
#define _CALCULATION_H

void input_Func(void); //Input function of text.
void input_Area(void); //Input function of Area. **** FIXED NOW MATCHES THE .CPP file
void input_Trap(void); //Input function of Trapezoid.  *** STILL BUGGED .CPP says it returns a float this says void
float rectangle_Area (float , float); //Declaration for Rectangle Area.
float trapezoid_Area (float , float, float); //Declaration for Trapezoid Area.

#endif

float input_Area(void)  // ** Pt1 here you declare you are going to return a float
{
   float width = 0, length = 0, answer = 0;
   cout << "Enter the width of rectangle :";
   cin >> width;
   cout << "Enter the length of rectangle :";
   cin >> length;
   answer = rectangleArea(width, length);
   cout << "The area of Rectangle is : " << answer << endl;

   return (answer);        // * So return the answer like you said you would at Pt1
}

#ifndef _CALCULATION_H
#define _CALCULATION_H

void input_Func(void); //Input function of text.
float input_Area(void); //Input function of Area. **** FIXED NOW MATCHES THE .CPP file above
void input_Trap(void); //Input function of Trapezoid.  *** STILL BUGGED .CPP says it returns a float this still says void
float rectangle_Area (float , float); //Declaration for Rectangle Area.
float trapezoid_Area (float , float, float); //Declaration for Trapezoid Area.

#endif

#ifndef _CALCULATION_H
#define _CALCULATION_H

float RectangleArea (float width, float length);
float TrapezoidArea (float base1, float base2, float height); 

#endif

#include "Calculation.h"

//Calculation of Rectangle Area.
float RectangleArea(float width, float length)
{
	float Area_Rectange;
	Area_Rectange = width * length;
	return (Area_Rectange);
}

//Calculation of Trapezoid Area.
float TrapezoidArea(float base1, float base2, float height)
{
	float Area_Trapezoid;
	Area_Trapezoid = height * (base1 + base2) / 2;
	return (Area_Trapezoid);
}

#ifndef _INPUT_H
#define _INPUT_H

/* Asks user for menu choice up to given max value */
unsigned int MenuInput (char* prompt, unsigned int maxNum);

/* Asks user for a float within given range, with prompt text */
float GetFloatInput(char* prompt, float min, float max);

#endif

#include <iostream>
#include "input.h"

/* Asks user for menu choice up to given max value */
unsigned int MenuInput(char* prompt, unsigned int maxNum) {
	bool validFlag = false;
	unsigned int iResult;
	do {
		printf(prompt);												// Put prompt on screen	
		int err = scanf_s("%u", &iResult);							// Scan for a unsigned int and hold any error
		if ((err == 0) || (iResult > maxNum)) {						// Check value between 0 .. maxNum
			printf("Invalid menu choice try again\n");				// If value is invalid .. prompt that
		} else validFlag = true;									// Value is valid
		scanf_s("%*[^\n]");											// Make sure we dump any characters in buffer
	} while (validFlag == false);									// Loop until valid
	return (iResult);												// Return result
}

/* Asks user for a float within given range, with prompt text */
float GetFloatInput (char* prompt, float min, float max) {
	int err;
	float fResult;
	do {
		printf(prompt);												// Put prompt on screen	
		err = scanf_s("%f", &fResult);								// Scan for a float and hold any error
		if (err == 0) {												// Err = zero means entry is not a float
			printf("Entry is not a float try again\n");				// Prompt entry was not a float to screen
		} else {
			if (fResult < min) {									// Check entry is above minimum 
				printf("Re-enter value below minimum of %f\n", min);// Prompt that on screen
				err = 0;											// Set err to zero so we fail loop
			}
			if (fResult > max) {									// Check entry is below maximum 
				printf("Re-enter value above maximum of %f\n", max);// Prompt that on screen
				err = 0;											// Set err to zero so we fail loop
			}
		}
		scanf_s("%*[^\n]");											// Make sure we dump any characters in buffer
	} while (err == 0);												// Repeat until valid float
	return (fResult);												// Return the  result
} 

#include <iostream>
#include "calculation.h"
#include "input.h"
using namespace std;

float input_area (void) {
	float width = GetFloatInput("Enter the width of rectangle :", FLT_EPSILON, FLT_MAX);
	float height = GetFloatInput("Enter the length of rectangle :", FLT_EPSILON, FLT_MAX);
	return (RectangleArea(width, height));							//Function Call to Rectangle and return answer
}

float input_trap(void) {
	float base1 = GetFloatInput("Enter base1 of trapezoid : ", FLT_EPSILON, FLT_MAX);
	float base2 = GetFloatInput("Enter base2 of trapezoid : ", FLT_EPSILON, FLT_MAX);
	float height = GetFloatInput("Enter the height of trapezoid : ", FLT_EPSILON, FLT_MAX);
	return (TrapezoidArea(base1, base2, height));					//Function Call to Trapezoid and return answer
}

int main()
{
	bool exitFlag = false;
	/* Menu */
	while (!exitFlag){
		printf("\nMain Menu:\n");
		printf("	0) Exit program\n");
		printf("	1) Calculate area of rectangle\n");
		printf("	2) Calculate area of trapezoid\n");
		unsigned int choice = MenuInput("Enter your choice : ", 2);
		switch (choice) {
			case 1:
				printf("Area of rectangle = %f\n", input_area());
				break;
			case 2:
				printf("Area of trapezoid = %f\n", input_trap());
				break;	
			default:
				exitFlag = true;
		}
	};

	return 0;
}

#include <iostream>
#include <float.h>         // Added to define FLT_EPSILON & FLT_MAX
#include "calculation.h"
#include "input.h"
using namespace std;

#include <iostream>
#include "calculation.h"
#include "input.h"     // <----- GetFloatInput is defined in this include>
using namespace std;

int main(int argc, char**argv)