C++ Keywords: Complete Reference Guide

// if, else, for, while, break, continue
#include 
using namespace std;

int main() {
    // if-else statement
    int x = 10;
    if (x > 5) {
        cout << "x is greater than 5" << endl;
    } else {
        cout << "x is 5 or less" << endl;
    }
    
    // for loop with break and continue
    for (int i = 0; i < 10; i++) {
        if (i == 2) {
            continue; // Skip iteration when i is 2
        }
        if (i == 8) {
            break; // Exit loop when i is 8
        }
        cout << i << " ";
    }
    
    // while loop
    int count = 0;
    while (count < 5) {
        cout << "Count: " << count << endl;
        count++;
    }
    
    return 0;
}

// auto, nullptr, constexpr, noexcept, decltype
#include 
#include 
using namespace std;

// constexpr function (compile-time computation)
constexpr int factorial(int n) {
    return (n <= 1) ? 1 : n * factorial(n - 1);
}

// noexcept function (no exception guarantee)
void safe_function() noexcept {
    cout << "This function won't throw exceptions" << endl;
}

int main() {
    // auto type deduction
    auto x = 42;           // x is int
    auto y = 3.14;         // y is double
    auto z = "hello";      // z is const char*
    
    // nullptr instead of NULL
    int* ptr = nullptr;
    if (ptr == nullptr) {
        cout << "Pointer is null" << endl;
    }
    
    // constexpr variable (compile-time constant)
    constexpr int max_size = factorial(5); // Computed at compile-time
    cout << "Max size: " << max_size << endl;
    
    // decltype - get type from expression
    int a = 10;
    decltype(a) b = 20; // b is int
    cout << "Type of b: " << typeid(b).name() << endl;
    
    return 0;
}