Comments on: 3.8 — Bitwise operators http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/ Wed, 20 Aug 2008 08:27:13 +0000 http://wordpress.org/?v=2.5.1 By: Learn C++ - » 14.5 — Class template specialization http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-24085 Learn C++ - » 14.5 — Class template specialization Mon, 18 Aug 2008 03:00:04 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-24085 [...] how the bit-logic works in order to use the class (though here’s a link to the lesson on bitwise operators if you want to figure it out, but need a refresher on how bitwise operators [...] [...] how the bit-logic works in order to use the class (though here’s a link to the lesson on bitwise operators if you want to figure it out, but need a refresher on how bitwise operators [...]

]]> By: Argon http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-23495 Argon Wed, 13 Aug 2008 01:26:27 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-23495 Phun to look at ASCII table and how it is built up regarding bitwise operations. I.e. Converting from upper to lower case. A=65=01000001 a=97=01100001   32=00100000 So 65^32 (or A^32) gives 97 (or a). So 97^32 (or a^32) gives 65 (or A). #include <iostream> int main() {     using namespace std;     char chX,chX32;     for(int i=65;i<91;i++)     {         chX = i;     chX32 = i^32;     cout << i << ":t" << chX << "tt" << int(chX32) << ":t" << chX32 << "tt";     chX32 = chX32^32;     cout << int(chX32) << ":t" << chX32 << endl;     }     return 0; } Phun to look at ASCII table and how it is built up regarding bitwise operations.
I.e. Converting from upper to lower case.

A=65=01000001
a=97=01100001
  32=00100000

So 65^32 (or A^32) gives 97 (or a).
So 97^32 (or a^32) gives 65 (or A).

#include <iostream>

int main()
{
    using namespace std;
    char chX,chX32;
    for(int i=65;i<91;i++)
    {
        chX = i;
    chX32 = i^32;
    cout << i << ":t" << chX << "tt" << int(chX32) << ":t" << chX32 << "tt";
    chX32 = chX32^32;
    cout << int(chX32) << ":t" << chX32 << endl;
    }
    return 0;
}

]]> By: Alex http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20677 Alex Fri, 11 Jul 2008 01:49:12 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20677 x <<= y is the same as x = x << y. Because of this, 3 <<= 1 is the same as 3 = 3 << 1, which obviously makes no sense since you can't assign a value to the number 3! x <<= y is the same as x = x << y. Because of this, 3 <<= 1 is the same as 3 = 3 << 1, which obviously makes no sense since you can’t assign a value to the number 3!

]]> By: boudiaf http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20587 boudiaf Wed, 09 Jul 2008 15:11:25 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20587 3 << 1 returns 6 whereas 3 <<= 1 does not compile since "3" is not a variable name... int x = 3; x = x << 1 ; and int x = 3 ; x <<= 1 ; are equivalent; eventually x = 6. 3 << 1 returns 6 whereas 3 <<= 1 does not compile since “3″ is not a variable name…

int x = 3; x = x << 1 ; and int x = 3 ; x <<= 1 ; are equivalent; eventually x = 6.

]]> By: moonrat http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20586 moonrat Wed, 09 Jul 2008 14:30:04 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20586 From what I understand, the end answer is the same, but in the second case the 3 itself changes to 6 (3 becomes bitwise shifted to the left 1, which is decimal 6). Whereas in the first case 3 stays 3 even after the operation; you'd need an x = 3 << 1 for example for it to have any context. From what I understand, the end answer is the same, but in the second case the 3 itself changes to 6 (3 becomes bitwise shifted to the left 1, which is decimal 6). Whereas in the first case 3 stays 3 even after the operation; you’d need an x = 3 << 1 for example for it to have any context.

]]> By: Stuart http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20065 Stuart Sun, 29 Jun 2008 22:20:04 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-20065 What's the difference in these: 3 << 1 and 3 <<= 1? What’s the difference in these: 3 << 1 and 3 <<= 1?

]]> By: Learn C++ - » 3.7 — Converting between binary and decimal http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-12645 Learn C++ - » 3.7 — Converting between binary and decimal Wed, 23 Apr 2008 02:37:57 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-12645 [...] 2007 Prev/Next Posts « 3.6 — Logical operators | Home | 3.8 — Bitwise operators » Sunday, June 17th, 2007 at 11:14 [...] [...] 2007 Prev/Next Posts « 3.6 — Logical operators | Home | 3.8 — Bitwise operators » Sunday, June 17th, 2007 at 11:14 [...]

]]> By: Cody http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-4791 Cody Sat, 22 Dec 2007 15:16:33 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-4791 When you do the compound XOR expression the result 0101 would equal 5 not 1. [ Fixed. -Alex ] When you do the compound XOR expression the result 0101 would equal 5 not 1.

[ Fixed. -Alex ]

]]> By: Cody http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-4790 Cody Sat, 22 Dec 2007 15:13:26 +0000 http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/#comment-4790 you put in the table that AND, OR, and XOR flip all digits in x but they do not. [ Aah, the perils of copy and paste. :) Fixed. -Alex ] you put in the table that AND, OR, and XOR flip all digits in x but they do not.

[ Aah, the perils of copy and paste. :) Fixed. -Alex ]

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