# C Program to Add Two Numbers using Function

The program takes two numbers from the user as input and prints their sum on the screen as output.

Sample Input:

``Enter two numbers: 10 20``

Output:

``Sum of the two numbers is: 30``

To calculate the sum of two numbers, we have defined a function `add()` which takes two numbers as arguments and returns their sum.

```// C program to add two numbers using a function
#include <stdio.h>

// Function declaration

int main(){

int num1, num2, res;

printf("Enter two numbers: ");
scanf("%d %d", &num1, &num2);

// Print the result
printf("Sum of the two numbers is: %d", res);

return 0;

}

// User defined function to add two numbers
int sum;
sum = a + b;
return sum;
}

```

Output:

```Enter two numbers: 10 20
Sum of the two numbers is: 30```

### Code Explanation:

• The program takes two numbers as input from the user and stores them in the `num1` and `num2` variables respectively.
• To get the sum of the two numbers, we have defined a function `add()`. The `add()` function takes two arguments and returns their sum.
• The sum returned by the `add()` function is stored in the `res` variable.
• Finally, the sum of the two numbers is printed on the screen using the print() function.

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