# Four Function Calculator Program in C programming

By | June 22, 2019

“Four Function Calculator Program” is a C program to input first number, an operator and second number to perform required calculation. A sample input string is 2+4 [Press Enter]. The 4 function calculator program will add 2 and 4 and display the answer of addition that is 6.

The operators may be arithmetic operators for:

2. subtraction –
3. multiplication *
4. division /

This C program uses if else if statement to check whether operator is +, -, * or / and performs the related mathematical operation and show result to the user.

The source code for plus, minus, multiplication and division calculator in C programming language is in the following code block with syntax coloring.

```/*
Write a C program to work as
4 function calculator +, _, *, /
Sample input string may be
20+30[Press Enter]
The c program will show answer 50
*/
#include<stdio.h>
int main()
{
char operator;
float num1, num2, result;
/* Input a number operator and second number from user */
printf("Enter firrst number operaor second number[ENTER]:");
printf("\nExample:  10+20[Enter]: ");
scanf("%f%c%f", &num1,&operator,&num2);

/* check the operator and perform operation
accordingly */
if( operator=='+')
{
result= num1+num2;
}
else if (operator =='-')
{
result = num1- num2;
printf("Subtraction=%.2f",result);
}
else if (operator =='*')
{
result = num1 * num2;
printf("Multiplication=%.2f",result);
}
else if (operator =='/')
{
result = num1 / num2;
printf("Division=%.2f",result);
}
else
printf("Invalid operator please input +, -, *, / ") ;
return 0;
}
```