Example: Sum of Natural Numbers using for loop in C++

C
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C#
Java
Python
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// Sum of Natural Numbers using for loop
#include <iostream> // Required for input/output operations

int main() {
    // Step 1: Declare variables to store the input number and the sum
    int n;
    int sum = 0; // Initialize sum to 0 before accumulation

    // Step 2: Prompt the user to enter a positive integer
    std::cout << "Enter a positive integer: ";
    std::cin >> n; // Read the user's input into variable 'n'

    // Step 3: Use a for loop to iterate from 1 to n
    // The loop variable 'i' will take values 1, 2, 3, ..., n
    for (int i = 1; i <= n; ++i) {
        sum += i; // Add the current number 'i' to the 'sum'
    }

    // Step 4: Display the calculated sum
    std::cout << "The sum of natural numbers up to " << n << " is: " << sum << std::endl;

    return 0; // Indicate successful program execution
}