C/C++ Logical and Bitwise Operators

Introduction

A simple note of C/C++ Logical and Bitwise Operators

Code

#include <iostream>
using namespace std;

/** some practice of logical operators
 * and bitwise operators
 */
int main () {

    cout << endl;
    cout << "\tLogical operators" << endl;
    // && (Logical AND)
    // All true -> true
    // Any false -> false
    cout << "\ttrue && true && true\t -> \t" << (true && true && true? "true" : "false") << endl;
    cout << "\ttrue && true && false\t -> \t" << (true && true && false? "true" : "false") << endl;
    // || (Logical OR)
    // Any true -> true
    // All false -> false
    cout << "\tfalse || false || true\t -> \t" << (false || false || true? "true" : "false") << endl;
    cout << "\tfalse || false || false\t -> \t" << (false || false || false? "true" : "false") << endl;
    // ! (Logical NOT)
    // inverse the value
    cout << "\t!true\t\t\t -> \t" << (!true? "true" : "false") << endl;
    cout << "\t!false\t\t\t -> \t" << (!false? "true" : "false") << endl << endl;

    cout << "\tBitwise operators" << endl;
    // & (Bitwise AND)
    // 0 & any -> 0
    // 1 & 1 -> 1
    // 3 & 5 -> 0011 & 0101 = 0001 -> 1
    cout << "\t3 & 5\t\t\t -> \t" << (3 & 5) << endl;

    // | (Bitwise Inclusive OR)
    // 1 | any -> 1
    // 0 | 0 -> 0
    // 3 | 5 -> 0011 | 0101 = 0111 -> 7
    cout << "\t3 | 5\t\t\t -> \t" << (3 | 5) << endl;

    // ^ (Bitwise Exclusive OR)
    // 0 ^ 0 -> 0
    // 1 ^ 1 -> 0
    // 1 ^ 0 -> 1
    // 0 ^ 1 -> 1
    // 3 ^ 5 -> 0011 ^ 0101 = 0110 -> 6
    cout << "\t3 ^ 5\t\t\t -> \t" << (3 ^ 5) << endl;

    // << (Shift Left)
    // 0001 << 1 -> 0010
    // 0001 << 2 -> 0100
    // shift all bits to left side and add 0 to right side,
    // the left side bits will be dropped,
    // e.g., 100...001 << 1 -> 00...010
    // 
    // can use it as *2 operation 
    // 3 << 1 -> 0011 << 1 = 0110 -> 6 (3*2)
    // 3 << 2 -> 0011 << 2 = 1100 -> 12 (3*2*2)
    cout << "\t3 << 1\t\t\t -> \t" << (3 << 1) << endl;
    cout << "\t3 << 2\t\t\t -> \t" << (3 << 2) << endl;

    // << (Shift Right)
    // 0100 >> 1 -> 0010
    // 0100 >> 2 -> 0001
    // shift all bits to right side and
    // add 0 or 1 (depends on system) to left side,
    // the right side bits will be dropped,
    // e.g., ...00011 >> 1 -> ...0001
    // 
    // can use it as /2 operation 
    // 12 >> 1 -> 1100 >> 1 = 0110 -> 6 (12/2)
    // 12 >> 2 -> 1100 >> 2 = 0011 -> 3 (12/2/2)
    cout << "\t12 >> 1\t\t\t -> \t" << (12 >> 1) << endl;
    cout << "\t12 >> 2\t\t\t -> \t" << (12 >> 2) << endl;

    // ~ (Unary complement (bit inversion))
    // 0 -> 1
    // 1 -> 0
    // ~ (char) -128 -> ~10000000 = 01111111 -> 127
    cout << "\t ~(char)-128\t\t -> \t" << ~(char)-128 << endl;
    cout << endl;

    system("PAUSE");
    return 0;
}

Result

Reference

http://www.cplusplus.com/doc/tutorial/operators/
http://en.wikipedia.org/wiki/Bitwise_operation


Download

File at github
https://github.com/benbai123/C_Cplusplus_Practice/blob/master/CPP/CPP_Basic/logical_and_bitwise_operator.cpp