How can I reprogram this in such a way that, that I don't need to use any sort of variable?-CodePudding

This my code:

#include <stdio.h>
#include <conio.h>


int processChoice()
{
    int choice = -1; //I need to execute this code without using any variable
    printf("\nMake a Choice (1, 2, 3 or 0): ");
    scanf("%d",&choice);
    printf("%d",choice);
    
    switch(choice)
    {
        case 0:
        printf("\nExiting...\n");
        break;
        case 1:
        printf("\nDrawing rectangle...\n");
        break;
        case 2:
        printf("\nDrawing Right triangle...\n");
        break;
        case 3:
        printf("\nDrawing isosceles triangle...\n");
        break;
        
        default:
        printf("\n** Invalid Choice! **\n");
        choice = -1;
    }
    return choice;
}

void showMenu()
{
    printf("\nMenu:");
    printf("\n1. Draw Rectangle");
    printf("\n2. Draw Right triangle");
    printf("\n3. Draw isosceles triangle");
    printf("\n0. Exit program\n");
}


int main()
{
    int x = -1;
    do
    {
        showMenu();
      
    }while(processChoice() != 0);
    return 0;
}

That's my code here I used a variable "int Choice = -1;" I'm supposed to execute the same code without using any variable as per guidelines of my mentor.

I'm expecting the same code to be executed without using any variable.

CodePudding user response：

Maybe your mentor means that this declaration in main

int x = -1;

is not used and should be removed.

As for the function processChoice then in any case you need to enter a value from the user. I see the only possibility to write the function without using a variable the following way with using function getchar

int processChoice( void )
{
    printf("\nMake a Choice (1, 2, 3 or 0): ");
    
    switch( getchar() )
    {
        case '0':
        printf("\nExiting...\n");
        while ( getchar() != '\n' );
        return 0;

        case '1':
        printf("\nDrawing rectangle...\n");
        while ( getchar() != '\n' );
        return 1;

        case '2':
        printf("\nDrawing Right triangle...\n");
        while ( getchar() != '\n' );
        return 2;

        case '3':
        printf("\nDrawing isosceles triangle...\n");
        while ( getchar() != '\n' );
        return 3;
        
        default:
        printf("\n** Invalid Choice! **\n");
        while ( getchar() != '\n' );
        return -1;
    }
}

CodePudding user response：

/*I guess there are some communication barriers between you and your mentor XD 
It's easy follow these corrections
*/
#include <stdio.h>

#include <conio.h>


int processChoice() {
  int choice; //You're not required to use -1
  printf("\nMake a Choice (1, 2, 3 or 0): ");
  scanf("%d", & choice);
  printf("%d", choice);

  switch (choice) {
  case 0:
    printf("\nExiting...\n");
    break;               // Here  the code should be intended by at least one tab. It is a part of clean code..
  case 1:
    printf("\nDrawing rectangle...\n");
    break;
  case 2:
    printf("\nDrawing Right triangle...\n");
    break;
  case 3:
    printf("\nDrawing isosceles triangle...\n");
    break;

  default:
    printf("\n** Invalid Choice! **\n");
    choice; // default initializing to zero it is unecessary to use -1 here.
  }
  return choice;
}

void showMenu() {
  printf("\nMenu:");
  printf("\n1. Draw Rectangle");
  printf("\n2. Draw Right triangle");
  printf("\n3. Draw isosceles triangle");
  printf("\n0. Exit program\n");
}

int main() {
// Delete again initializing of this here aka int x = -1;
  do {
    showMenu();

  } while (processChoice() != 0);
  return 0;
}