Lesson 5: Iteration Mastery: for, while, do-while & Range-Based Loops

🔁 Loop Constructs in C++

Loops execute a block of code repeatedly as long as a specified condition remains true. Modern C++ (C++11 and higher) also introduces range-based for loops for effortless container traversal.

🔄 Loop Types Comparison

🎯 for (init; condition; update): Used when the exact number of iterations is known beforehand.

⏳ while (condition): Evaluates condition before executing the loop body.

🔁 do { ... } while (condition);: Executes body first, then checks condition (guarantees at least 1 run).

⚡ for (const auto& item : collection): Clean C++11 range-based loop for arrays and STL vectors.

💻 Code Example: Iteration & Range Traversal

⊞C++ Source Code (main.cpp)

#include <iostream>

#include <vector>

int main() {

// 1. Traditional for loop

std::cout << "--- Counting 1 to 5 ---" << std::endl;

for (int i = 1; i <= 5; ++i) {

std::cout << "Count: " << i << std::endl;

}

// 2. Range-based for loop (C++11)

std::vector<std::string> frameworks = {"Qt", "Unreal Engine", "Boost", "CUDA"};

std::cout << "

--- C++ High Performance Frameworks ---" << std::endl;

for (const auto& fw : frameworks) {

std::cout << "⚡ " << fw << std::endl;

}

return 0;

}

⊞Windows 11 Pro Terminal Execution OutputWindows 11 Pro Verified

⊞Administrator: Windows 11 Pro Command Prompt (g++ GCC 13.2.0)

—□✕

Microsoft Windows [Version 10.0.22631.3007] (Windows 11 Pro x86_64)

C:\Users\Student\CPP_Project>#include <iostream>

C:\Users\Student\CPP_Project> g++ -o main.exe main.cpp C:\Users\Student\CPP_Project> main.exe Hello World from C++ on Windows 11 Pro! [Process exited with code 0 in 0.001 seconds]

🛠️ Execution Output on ⊞ Windows 11 CMD:

⊞Command Execution Snippet

--- Counting 1 to 5 ---

Count: 1

Count: 2

Count: 3

Count: 4

Count: 5

--- C++ High Performance Frameworks ---

⚡ Qt

⚡ Unreal Engine

⚡ Boost

⚡ CUDA