Logical & Bitwise

Overview

Logical operators (&&, ||, !) combine conditions. Bitwise operators (&, |, ^, <<, >>) manipulate bits directly for high-performance tasks. Miscellaneous operators include `sizeof`.

Syntax

cpp

bool x = true, y = false;

// Logical
bool andRes = x && y; // false
bool orRes  = x || y; // true
bool notRes = !x;     // false

// Bitwise
int a = 5;  // 0101 in binary
int b = 3;  // 0011 in binary
int bitAnd = a & b;  // 0001 (1)
int bitXor = a ^ b;  // 0110 (6)
int leftShift = a << 1; // 1010 (10) - multiplies by 2

// Misc
int size = sizeof(a); // 4 bytes

Common Pitfalls

Confusing logical AND `&&` with bitwise AND `&`.

Interview Tips

Explain Short-Circuit Evaluation: In `(A && B)`, if A is false, B is never evaluated. This prevents errors like division by zero or null pointer dereferencing.
Bitwise operations are heavily tested in algorithmic interviews (e.g., checking if a number is a power of 2 using `(n & (n-1)) == 0`).

Real-World Example

Using logical operators for multiple conditions.

example

cpp

#include <iostream>
using namespace std;

int main() {
    int age = 25;
    bool hasLicense = true;
    
    if (age >= 18 && hasLicense) {
        cout << "Can drive!\n";
    }
    return 0;
}

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