Modules, using local scope

[ZoneDead]

How do you get the var's to move from main to a module, return that data and pass it on to the next module?

This is the code that i have come up with so far, I am attempting to make a program that calculates the area and perimeter of a rectangle.


#include <stdio.h>

//prototypes
void main();

void getUserInput();

void calculateArea();

void calculatePerimeter();

void outputToScreen();
////////////////////////////


void main(void)
{
int perimeter=0;

int length=0;

int width=0;

int area=0;
printf ("This program was created by John Low\n");
printf ("Please enter the width: ");

getUserInput();
//return 0;


} // end of main



void getUserInput(void)
{
scanf("%d", &width);
printf("Enter the length: \n");
scanf("%d", &lenght);

} // end of getUserInput


/*
void calculateArea(void)
{ &width * &length = area;

} // end of calculateArea



void calculatePerimeter(void)
{ &width * 2 + &length * 2= perimeter;

} // end of calculate Perimeter


void outputToScreen(void)
{ printf ("The area is: \n")
printf ("The perimeter is: \n")

}*/ // end of outputToScreen

I have nulled out the last little bit, because I was having difficulty getting the first module to work as it should.

 

[Salem]

For example

#include <stdio.h>

int input ( int *width, int *height ) {
    char buff[BUFSIZ];
    printf( "Enter width and height > " );
    fflush( stdout );
    if ( fgets( buff, BUFSIZ, stdin ) != NULL ) {
        if ( sscanf( buff, "%d %d", width, height ) == 2 ) {
            return 1;
        } else {
            fprintf( stderr, "Bad input\n" );
            return 0;
        }
    } else {
        return 0;
    }
}

int area ( int width, int height ) {
    return width * height;
}

int main ( ) {
    int width, height;
    if ( input( &width, &height ) ) {
        int result = area( width, height );
        printf( "Area of %dx%d is %d\n", width, height, result );
    }
    return 0;
}

--

 

[ZoneDead]

Salem, that does get me area, but is that modulated?

 

[Salem]

Sure, with a couple of prototypes, you can put input() in input.c and area() in area.c and put main() in main.c



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[ZoneDead]

/*
The final code completed
*/

#include <stdio.h>

//prototypes
void main(void);

int getUserInput(void);

int calculateArea(length, width);

int calculatePerimeter(width, length);

int outputToScreen(area, perimeter);
////////////////////////////


void main(void)
{
int perimeter=0;

int length=0;

int width=0;

int area=0;

printf ("This program was created by John Low\n");
printf ("-------------------------------------------------------\n");
printf ("Lab01 Calculating The Area and Perimeter of a Rectangle\n");

printf ("-------------------------------------------------------\n");
printf ("\n");
printf ("Please enter the width in whole numbers: ");

width=getUserInput();

printf ("Please enter the length in whole numbers: ");
length=getUserInput();


area= calculateArea(length, width);

perimeter= calculatePerimeter(length, width);

outputToScreen(area, perimeter);


} // end of main

/*********************************getUserInput************/
int getUserInput(void)
{ int x;

scanf("%d%*c",&x);
return x;
} // end of getUserInput


/*********************************calculateArea**********/
int calculateArea(int length, int width)
{ return width * length;

} // end of calculateArea


/********************************calculatePerimeter*******/
int calculatePerimeter(int width, int length)
{ return width * 2 + length * 2;

} // end of calculate Perimeter


/*************************outPutToscreeen*****************/
int outputToScreen(int area, int perimeter)
{ printf ("The area is: %d\n", area);
printf ("The perimeter is: %d\n", perimeter);
return 0;
} // end of outputToScreen

 

[Salem]

> void main(void);
1. There is no need to prototype main()
2. main returns an int - see my example

> int calculateArea(length, width);
You don't specify any types here
Try
int calculateArea(int length, int width);

> int outputToScreen(area, perimeter);
You may as well return void here, since you don't do anything with the answer.

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