Exercise: Sum Of Numbers


Use a for loop to compute the sum of all numbers from 14 to 73.

Once computed, print this sum to the console.

Introduction

In this lesson, we will learn how to compute the sum of a range of numbers using a for loop in C++. This is a fundamental concept in programming that helps in understanding loops and iteration. Summing numbers is a common task in various applications such as statistical calculations, data analysis, and algorithm development.

Understanding the Basics

Before diving into the solution, it's important to understand the basic structure of a for loop in C++. A for loop allows us to repeat a block of code a certain number of times. The syntax of a for loop is:

for (initialization; condition; increment) {
    // code to be executed
}

In this structure:

  • initialization sets the starting point of the loop.
  • condition is checked before each iteration; if it's true, the loop continues.
  • increment updates the loop variable after each iteration.

Main Concepts

To solve the problem, we need to:

  • Initialize a variable to store the sum.
  • Use a for loop to iterate from 14 to 73.
  • Add each number in this range to the sum variable.
  • Print the final sum.

Examples and Use Cases

Let's consider a simple example where we sum numbers from 1 to 5. The sum would be 1 + 2 + 3 + 4 + 5 = 15. Similarly, we can apply this logic to sum numbers from 14 to 73.

Common Pitfalls and Best Practices

Common mistakes include:

  • Incorrect loop boundaries, which can lead to off-by-one errors.
  • Forgetting to initialize the sum variable.
  • Not updating the loop variable correctly.
Best practices include:
  • Double-checking loop boundaries.
  • Ensuring the sum variable is initialized to 0.
  • Using meaningful variable names.

Advanced Techniques

For more advanced scenarios, consider using functions to encapsulate the summing logic, which can make the code more modular and reusable. Additionally, exploring other looping constructs like while loops or using the std::accumulate function from the C++ Standard Library can be beneficial.

Code Implementation

Here is the C++ code to compute the sum of numbers from 14 to 73:

#include <iostream>

int main() {
    // Initialize sum variable
    int sum = 0;
    
    // Use a for loop to iterate from 14 to 73
    for (int i = 14; i <= 73; ++i) {
        sum += i; // Add each number to sum
    }
    
    // Print the final sum
    std::cout << "The sum of numbers from 14 to 73 is: " << sum << std::endl;
    
    return 0;
}

This code initializes the sum to 0, iterates from 14 to 73, adds each number to the sum, and finally prints the result.

Debugging and Testing

To debug and test this code:

  • Check the loop boundaries to ensure they are correct.
  • Print intermediate values of the sum to verify the addition process.
  • Use a debugger to step through the loop and inspect variable values.

Thinking and Problem-Solving Tips

When approaching similar problems:

  • Break down the problem into smaller steps.
  • Write pseudocode to outline the logic before coding.
  • Test with small ranges to verify correctness before scaling up.

Conclusion

Summing a range of numbers using a for loop is a fundamental programming task that reinforces understanding of loops and iteration. Mastering this concept is crucial for tackling more complex problems in programming.

Additional Resources

For further reading and practice: