In this article, you will learn and get about creating a simple calculator program in C. Simple calculator means a calculator that performs four basic mathematical operation such as addition, subtraction, multiplication, and division. Here calculator program created in two ways:
To make a simple calculator in C programming that performs basic four mathematical operations, use the switch case to identify the input operator to perform the required calculation as shown in the program given below.
Here is a simple menu-driven program based on simple calculation like addition, subtraction, multiplication and division according to user's choice:
// Simple Calculator Program in C using switch case
// ----codscracker.com----
#include<stdio.h>
#include<conio.h>
int main()
{
float num1, num2, res;
int choice;
do
{
printf("1. Addition\n");
printf("2. Subtraction\n");
printf("3. Multiplication\n");
printf("4. Division\n");
printf("5. Exit\n\n");
printf("Enter Your Choice(1-5): ");
scanf("%d", &choice);
if(choice>=1 && choice<=4)
{
printf("\nEnter any two Numbers: ");
scanf("%f %f", &num1, &num2);
}
switch(choice)
{
case 1:
res = num1+num2;
printf("\nResult = %0.2f", res);
break;
case 2:
res = num1-num2;
printf("\nResult = %0.2f", res);
break;
case 3:
res = num1*num2;
printf("\nResult = %0.2f", res);
break;
case 4:
res = num1/num2;
printf("\nResult = %0.2f", res);
break;
case 5:
return 0;
default:
printf("\nWrong Choice!");
break;
}
printf("\n------------------------\n");
}while(choice!=5);
getch();
return 0;
}
This program was build and run under Code::Blocks IDE. Here is the initial snapshot of the sample run:
Now supply any input (as choice from 1 to 5) in a way that:
Let's suppose user enters 2 as his/her choice, so program will asks again to enter any two number to perform the subtraction. For example, if user enters 2 as choice and 20 as first number, then 10 as second number. Press ENTER key to see the output as shown in the snapshot given below:
Press 5 to exit the calculation process. Let's take a look at the explanation of this program.
After understanding the above program, it is easy to create the same program using function. So here is the calculator program that uses function in C.
// Simple Calculator Program in C using Function
// ----codscracker.com----
#include<stdio.h>
#include<conio.h>
float addFun(float, float);
float subFun(float, float);
float mulFun(float, float);
float divFun(float, float);
int main()
{
float num1, num2, res;
int choice;
do
{
printf("1. Addition\n");
printf("2. Subtraction\n");
printf("3. Multiplication\n");
printf("4. Division\n");
printf("5. Exit\n\n");
printf("Enter Your Choice(1-5): ");
scanf("%d", &choice);
if(choice>=1 && choice<=4)
{
printf("\nEnter any two Numbers: ");
scanf("%f %f", &num1, &num2);
}
switch(choice)
{
case 1:
res = addFun(num1, num2);
printf("\nResult = %0.2f", res);
break;
case 2:
res = subFun(num1, num2);
printf("\nResult = %0.2f", res);
break;
case 3:
res = mulFun(num1, num2);
printf("\nResult = %0.2f", res);
break;
case 4:
res = divFun(num1, num2);
printf("\nResult = %0.2f", res);
break;
case 5:
return 0;
default:
printf("\nWrong Choice!");
break;
}
printf("\n------------------------\n");
}while(choice!=5);
getch();
return 0;
}
float addFun(float a, float b)
{
return (a+b);
}
float subFun(float a, float b)
{
return (a-b);
}
float mulFun(float a, float b)
{
return (a*b);
}
float divFun(float a, float b)
{
return (a/b);
}
Here is the sample run of above program:
Here all the four function takes two floating-point values as its argument, does the operation and then return it to the main function. That is, its return value gets initialized to res variable. To learn about function in detail, then refer to Function in C tutorial.
