A simple program to create a Simple Calculator
#include<stdio.h>
#include<conio.h>
int add(int a,int b);
int substract(int b,int a);
int multiply(int a,int b);
int divide(int b,int a);
void doWork(char o);
void menu();
void option();
int input(int s);
void main()
{
clrscr();
freopen("simpcalc.txt","w",stdout);
menu();
option();
}
void menu()
{
printf("\n Press 1 to add");
printf("\n Press 2 to Substract");
printf("\n Press 3 to Multiply");
printf("\n Press 4 to Divide");
printf("\n Press 5 to Menu");
printf("\n Press 6 to Exit");
}
void option(){
char o;
printf("\n Press any valid Key:: ");
o=getche();
doWork(o);
}
int input(int s)
{
int a;
printf("\n Enter Number %d: ",s);
scanf("%d",&a);
return a;
}
void doWork(char o)
{
int r;
r=0;
switch(o)
{
case '1':
r=add(input(2),input(1));
printf("Result:: %d",r);
break;
case '2':
r=substract(input(1),input(2));
printf("Result:: %d",r);
break;
case '3':
r=multiply(input(2),input(1));
printf("Result:: %d",r);
break;
case '4':
r=divide(input(1),input(2));
printf("Result:: %d",r);
break;
case '5':
menu();
break;
case '6':
fclose(stdout);
exit(0);
break;
default:
option();
break;
}
option();
}
int add(int a,int b)
{
return a+b;
}
int substract(int b,int a)
{
return b-a;
}
int multiply(int a,int b)
{
return a*b;
}
int divide(int b,int a)
{
return b/a;
}
Output:
Press 1 to add
Press 2 to Substract
Press 3 to Multiply
Press 4 to Divide
Press 5 to Menu
Press 6 to Exit
Press any valid Key:: 1
Enter Number 1: 12
Enter Number 2: 12
Result:: 24
Press any valid Key:: 2
Enter Number 2: 14
Enter Number 1: 12
Result:: 2
Press any valid Key:: 3
Enter Number 1: 870
Enter Number 2: 2
Result:: 1740
Press any valid Key:: 4
Enter Number 2: 16
Enter Number 1: 14
Result:: 1
Press any valid Key:: 6
Limitation: The above program uses integer values only. No float or long values are used which will give erroneous results if the calculation goes to non-integral value.