C Program to Add Two Integers with Explanation and Output

Adding two numbers is one of the first things you’ll tackle in C programming. Let’s check out how to add two integers in C. Picture this: you've got 5 and 3. The program gives you their sum, which is 8.

This article shows you how to whip up a simple C program to add two integers, and it'll dive into each step involved.

Prerequisites for the C Program to Add Two Integers

Before we start, make sure you're familiar with these:

• Basic understanding of C programming syntax
• The int data type to store integer values
• Standard input and output functions like scanf and printf
• Any C compiler such as GCC 9 or newer — or just run it in the EduSeekho online compiler

Source Code of C Program to Add Two Integers

Here's the complete source code for adding two integers in C:

#include <stdio.h>

int main() {
    int a, b, sum;

    // Input two integers from the user
    printf("Enter the first integer: ");
    scanf("%d", &a);
    printf("Enter the second integer: ");
    scanf("%d", &b);

    // Calculate the sum
    sum = a + b;

    // Print the sum
    printf("Sum = %d\n", sum);

    return 0;
}

Output of the Add Two Integers Program

When you run this program, it will ask for two integers and display their sum. Here's a sample execution:

Enter the first integer: 5
Enter the second integer: 3
Sum = 8

Algorithm to Add Two Integers in C

Adding two integers involves reading them from the user, calculating their sum, and then displaying the result. Here is the step-by-step logic:

1. Read the first integer a from the user.
2. Read the second integer b from the user.
3. Calculate the sum of a and b.
4. Display the result of the addition.

flowchart TD
  A([Start]) --> B[/Read first integer a/]
  B --> C[/Read second integer b/]
  C --> D[sum = a + b]
  D --> E[/Print sum/]
  E --> F([End])

How the C Program to Add Two Integers Works

Let's break down the code line by line to see how it works.

• The line #include <stdio.h> includes the Standard Input Output library needed for functions like printf and scanf.
• The int main() function is where the program execution starts.
• We declare integer variables a, b, and sum to store the user inputs and the result.
• printf is used to prompt the user to enter the first integer.
• scanf("%d", &a) reads the integer input from the user and stores it in a.
• The process is repeated for the second integer b.
• The statement sum = a + b performs the addition of a and b.
• printf("Sum = %d\n", sum) prints the result on the screen.
• The program ends with return 0 indicating successful execution.

Time and Space Complexity of the C Program to Add Two Integers

This program efficiently handles the addition of two numbers with minimal resources.

Time Complexity: O(1). The program performs a constant amount of work independent of the input, as it only does a single addition operation.

Space Complexity: O(1). It uses only three integer variables: a, b, and sum.

Key takeaway: This program's a simple intro to arithmetic in C, showing how user input and basic calculations work together.

FAQs About C Program to Add Two Integers

Here are some common questions beginners have about this program:

Related Programs

If you found this program helpful, check out these related programs:

• C Program to Multiply Two Floating-Point Numbers
• C Program to Find Factorial of a Number
• C Program to Display Fibonacci Sequence with Example
• C Program to Compute Quotient and Remainder Easily
• C Program to Generate Multiplication Table with Example

Conclusion

When you’re dealing with user input, think about input validation — it'll make sure the entries are integers. It’ll help avoid unexpected behavior. Try tweaking this code to work with more numbers or even floating-point values. These skills will come in handy as you dive into more complex stuff.

Get more practice with C programming through our C programming quiz and try out new programs in the online compiler.