Cpp1_2.html

<article>
    <h1>C++ I: Page 2 - Variables & Primitives</h1>

    <section>
        <h2>The Building Blocks of Data</h2>
        <p>C++ is statically typed, meaning you must declare the type of a variable before using it. This allows the compiler to perform rigorous checks and optimize memory layout for specific data sizes.</p>
        
        <h3>The Code implementation</h3>
        <pre><code class="language-cpp">/*
 * File: primitives.cpp
 * Demonstration of C++ primitive types, type modifiers, and type inference
 */
#include &lt;iostream&gt;
#include &lt;string&gt;
#include &lt;limits&gt; // For numerical limits
#include &lt;typeinfo&gt; // For typeid

using namespace std;

// Enum for readable state constants
enum State { IDLE, RUNNING, ERROR };

// Struct for grouping related primitives
struct UserProfile {
    int id;
    double balance;
    bool isActive;
};

// Function to print type info
void PrintTypeInfo(const char* name, const auto& val) {
    cout << name << " type: " << typeid(val).name() << endl;
}

int main() {
    // 1. Integer types with modifiers
    short s = 10;            // Usually 2 bytes
    int i = 1000;            // Usually 4 bytes
    long l = 1000000L;       // Usually 4 or 8 bytes
    unsigned int ui = 500U;  // Only non-negative

    // 2. Floating point
    float f = 3.14f;
    double d = 3.1415926535;

    // 3. Characters and Strings
    char c = 'A';
    string str = "Hello C++";

    // 4. Boolean
    bool isRunning = true;

    // 5. Constants (Cannot be modified)
    const int MAX_USERS = 100;
    
    cout << "--- Primitive Types Summary ---" << endl;
    cout << "Integer: " << i << endl;
    cout << "Double: " << d << endl;
    cout << "String: " << str << endl;
    
    // 6. Modern C++: Type Inference with 'auto'
    auto inferredInt = 100;        // Deduced as int
    auto inferredDouble = 5.5;      // Deduced as double
    
    PrintTypeInfo("inferredInt", inferredInt);
    
    // 7. Using the struct
    UserProfile user = {1, 150.50, true};
    cout << "User ID: " << user.id << " | Balance: " << user.balance << endl;

    // 8. Sizeof operator for platform inspection
    cout << "Size of int: " << sizeof(int) << " bytes" << endl;
    cout << "Size of double: " << sizeof(double) << " bytes" << endl;

    return 0;
}

/*
 * C++ Type System Nuances:
 * 1. sizeof(type) helps determine platform-specific size, critical for memory optimization.
 * 2. Unsigned types cannot represent negative numbers; useful for counting/size values.
 * 3. 'const' keyword ensures data immutability, allowing compiler optimizations.
 * 4. 'auto' keyword (C++11+) simplifies code by letting the compiler deduce types.
 * 5. Structs are lightweight containers for data; class-like behavior without 
 *    the default private access modifier (by default, structs are public).
 * 6. typeid operator is useful for runtime type information (RTTI), 
 *    though often used sparingly in performance-critical paths.
 * 7. Enums provide named integral constants, improving code readability.
 */
        </code></pre>
        <div class="interactive-sim">
            <h3>Variable Simulator</h3>
            <button class="sim-button" onclick="
                const out = document.getElementById('sim-output-cpp1_2');
                out.innerHTML = 'int x = 10; int y = 20;<br>';
                setTimeout(() => out.innerHTML += '>> Sum = ' + (10 + 20), 800);
            ">Run Simulation</button>
            <div id="sim-output-cpp1_2" class="sim-output"></div>
        </div>
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