ProgrammingExamples - User contributions [en]

Talk:CPP

2010-07-01T21:49:34Z

Bench: Created page with ' == The purpose of articles == I have a few thoughts about the direction of some articles on this page Lets aim to keep all articles on the point of "how do i solve a real-worl…'

== The purpose of articles ==

I have a few thoughts about the direction of some articles on this page

Lets aim to keep all articles on the point of "how do i solve a real-world problem" rather than "how do i use feature X of the language". This is for a variety of reasons:

* C++ reference sites which describe language syntax are everywhere. This site is never going to rival MSDN no matter how hard we try, so lets not bother trying :-)
* Examples describing language syntax or library generally need a wordy explanation to be useful/meaningful
* the questions which are frequently asked on forums are rarely of the form "how do i use <some language feature>" (OK, that's actually not true, but such questions rightly get answered with "RTFM" or "STFW").
* Ensuring each example serves a clear, distinctive purpose - So, "Tabular text output" would be a better context than "<iomanip> example usage".
* Addressing a familiar concrete problem is often better to help novices ''connect the dots'' as they build up their repertoire of problem solving techniques.
* Articles which talk about a single language feature are often contrived using "weird" techniques to solve problems in a way which makes no sense; such articles do more harm than good, since readers will always expect to see the ''right'' way to solve a problem. There are already too many pages on the internet which encourage bad habits, so lets avoid that trap.

CPP

2010-06-27T09:37:29Z

Bench: Migrated C-style code to its own section to distinguish them from constructs which generally replace those techniques in C++

= C++ =
A statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as a "middle-level" language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell Labs as an enhancement to the C programming language and originally named C with Classes. It was renamed C++ in 1983. (http://en.wikipedia.org/wiki/C++)
----
=== Programming Examples ===
* [[CPP/AlphebetizeString|Alphabetize a vector of strings]]
* [[CPP/ZeroPad|Pad a number with zeros]]
* [[CPP/BinaryIO|Binary input and output]]
* [[CPP/ExecuteLinuxCommand|Execute a linux command]]
* [[CPP/Casting|Casting]]
* [[CPP/KeyboardInput|Keyboard input]]
* [[CPP/CommandLineArguments|Command line arguments]]
* [[CPP/DeepCopy|Deep copy]]
* [[CPP/DefaultArguments|Default arguments]]
* [[CPP/Enum|Enum]]
* [[CPP/Exceptions|Exceptions]]
* [[CPP/Infinity|Infinity]]
* [[CPP/Logging|Logging]]
* [[CPP/Namespaces|Namespaces]]
* [[CPP/NAN|NAN (not a number)]]
* [[CPP/OverloadOperator|Overload operator]]
* [[CPP/ParallelSort|Parallel sort]]
* [[CPP/RandomNumbers|Random numbers]]
* [[CPP/StringStream|StringStream]]
* [[CPP/Struct|Struct]]
* [[CPP/Switch|Switch]]
* [[CPP/Typedef|Typedef]]

=== I/O ===
* [[CPP/IO/Setw|Column width (setw)]]
* [[CPP/IO/FileInput|File input]]
* [[CPP/IO/FileOutput|File output]]
* [[CPP/IO/ReadingLines|Reading lines from a text file]]

=== Strings ===
* [[CPP/Strings/Compare|Compare strings]]
* [[CPP/Strings/Concatenate|Concatenate]]
* [[CPP/Strings/CountCharacters|Count characters]]
* [[CPP/Strings/Split|Split]]
* [[CPP/Strings/Case_Conversion|Case conversion]]

=== Classes ===
* [[CPP/Classes/ClassTemplate|Class template]]
* [[CPP/Classes/ConstructorInheritance|Constructor inheritance]]
* [[CPP/Classes/InitializationList|Initialization list]]
* [[CPP/Classes/DerivedClass|Derived class]]
* [[CPP/Classes/DownCasting|Down casting]]
* [[CPP/Classes/FriendClass|Friend class]]
* [[CPP/Classes/NestedClasses|Nested classes]]
* [[CPP/Classes/PureVirtualFunction|Pure virtual function]]
* [[CPP/Classes/Singleton|Singleton]]

=== Loops ===
* [[CPP/Loops/DoWhile|Do while]]
* [[CPP/Loops/While|While]]
* [[CPP/Loops/For|For]]

=== STL Data Structures ===
*[[CPP/STL/String|String]]
*[[CPP/STL/Vector|Vector]]
*[[CPP/STL/List|List]]
*[[CPP/STL/Set|Set]]
*[[CPP/STL/MultiSet|MultiSet]]
*[[CPP/STL/Map|Map]]
*[[CPP/STL/MultiMap|MultiMap]]
*[[CPP/STL/Pair|Pair]]
*[[CPP/STL/PriorityQueue|Priority queue]]
*[[CPP/STL/Queue|Queue]]
*[[CPP/STL/Tuple|Tuple]]

=== STL Algorithms ===
*[[CPP/STL/RandomShuffle|Random shuffle]]
*[[CPP/STL/Sort|Sort]]

=== Debugging ===
* [[CPP/Debugging/Assert|Assert]]
* [[CPP/Debugging/LineNumbers|LineNumbers]]

=== C++ TR1 ===

*[[CPP/TR1/Regex_Tokenising|Tokenising with RegEx]]

=== C++0x ===
*[[CPP/C++0x/Hash|Hash]]

=== Math ===
*[[CPP/Math/Exponential|Exponential function]]
*[[CPP/Math/MinMax|Min and Max]]
*[[CPP/Math/Trig|Trig functions]]

=== C-Style Programming Techniques ===
* [[CPP/Array|Array]]
* [[CPP/2DArray|2D Array]]
* [[CPP/CharacterArray|Character array]]
* [[CPP/Macros|Macros]]
* [[CPP/FunctionPointer|Function pointer]]
* [[CPP/VariableNumberOfArguments|Variable number of function arguments]]

CPP/TR1/Regex Tokenising

2010-06-26T15:47:56Z

Bench: Vertical spacing/alignment

<source lang="cpp">#include <string>
#include <algorithm> // copy
#include <iterator> // back_inserter, ostream_iterator
#include <iostream>
#include <regex> // regex, sregex_token_iterator
#include <vector>

int main()
{
//flag to switch off submatching
static const int submatch_off = -1;

std::string str = "the\t quick brown\n-\n- fox jumped..over,the,lazy,.dog";
std::vector<std::string> tokens;
std::tr1::regex re("[\\s-,.]+");

//start/end points of tokens in str
std::tr1::sregex_token_iterator
begin(str.begin(), str.end(), re, submatch_off),
end;

std::copy(begin, end, std::back_inserter(tokens));

std::copy(tokens.begin(), tokens.end(),
std::ostream_iterator<std::string>(std::cout, "\n"));
}
</source>

CPP/TR1/Regex Tokenising

2010-06-26T15:47:03Z

Bench: Show tokenising on punctuation as well as whitespace

CPP/TR1/Regex Tokenising

2010-06-26T15:41:50Z

Bench: Boost/TR1 Regular Expressions - Tokenising on multiple consecutive delimiters

<source lang="cpp">
#include <string>
#include <algorithm> // copy
#include <iterator> // back_inserter, ostream_iterator
#include <iostream>
#include <regex> // regex, sregex_token_iterator
#include <vector>

int main()
{
//flag to switch off submatching
static const int submatch_off = -1;

std::string str = "the\t quick brown\n\n fox jumped over the lazy dog";
std::vector<std::string> tokens;
std::tr1::regex re("[\\s]+");

//start/end points of tokens in str
std::tr1::sregex_token_iterator
begin(str.begin(), str.end(), re, submatch_off),
end;

std::copy(begin, end, std::back_inserter(tokens));

std::copy(tokens.begin(), tokens.end(),
std::ostream_iterator<std::string>(std::cout, "\n"));
}
</source>

Main Page

2010-06-26T15:39:17Z

Bench: /* C++ */

==Welcome to ProgrammingExamples.net!==
This site is intended to provide short, compilable code snippets demonstrating frequently used concepts in several programming languages. Please feel free to modify the existing examples, and add new examples!

=="Do"s and "Don't"s==

=== "Do"s ===
* Try to keep each example as short as possible.
* Try to demonstrate a single concept per example.
* Comment, comment, comment!

=== "Don't"s ===
* Do not treat the wiki as your own personal code dump. Things that are placed here should be useful for many people.

== Coding Standards ==
We don't want to get too carried away here, but below are some guidelines.

* Try to use a sensible indentation scheme.
* Use descriptive variable names.
* Comment, comment, comment!

__TOC__

== C++ ==
* [[CPP/AlphebetizeString|Alphabetize a vector of strings]]
* [[CPP/ZeroPad|Pad a number with zeros]]
* [[CPP/Array|Array]]
* [[CPP/2DArray|2D Array]]
* [[CPP/BinaryIO|Binary input and output]]
* [[CPP/ExecuteLinuxCommand|Execute a linux command]]
* [[CPP/Casting|Casting]]
* [[CPP/CharacterArray|Character array]]
* [[CPP/KeyboardInput|Keyboard input]]
* [[CPP/CommandLineArguments|Command line arguments]]
* [[CPP/DeepCopy|Deep copy]]
* [[CPP/DefaultArguments|Default arguments]]
* [[CPP/Enum|Enum]]
* [[CPP/Exceptions|Exceptions]]
* [[CPP/FunctionPointer|Function pointer]]
* [[CPP/Infinity|Infinity]]
* [[CPP/Logging|Logging]]
* [[CPP/Macros|Macros]]
* [[CPP/Namespaces|Namespaces]]
* [[CPP/NAN|NAN (not a number)]]
* [[CPP/OverloadOperator|Overload operator]]
* [[CPP/ParallelSort|Parallel sort]]
* [[CPP/RandomNumbers|Random numbers]]
* [[CPP/StringStream|StringStream]]
* [[CPP/Struct|Struct]]
* [[CPP/Switch|Switch]]
* [[CPP/Typedef|Typedef]]
* [[CPP/VariableNumberOfArguments|Variable number of function arguments]]

=== I/O ===
* [[CPP/IO/Setw|Column width (setw)]]
* [[CPP/IO/FileInput|File input]]
* [[CPP/IO/FileOutput|File output]]
* [[CPP/IO/ReadingLines|Reading lines from a text file]]

=== Strings ===
* [[CPP/Strings/Compare|Compare strings]]
* [[CPP/Strings/Concatenate|Concatenate]]
* [[CPP/Strings/CountCharacters|Count characters]]
* [[CPP/Strings/Split|Split]]
* [[CPP/Strings/Case_Conversion|Case conversion]]

=== Classes ===
* [[CPP/Classes/ClassTemplate|Class template]]
* [[CPP/Classes/ConstructorInheritance|Constructor inheritance]]
* [[CPP/Classes/InitializationList|Initialization list]]
* [[CPP/Classes/DerivedClass|Derived class]]
* [[CPP/Classes/DownCasting|Down casting]]
* [[CPP/Classes/FriendClass|Friend class]]
* [[CPP/Classes/NestedClasses|Nested classes]]
* [[CPP/Classes/PureVirtualFunction|Pure virtual function]]
* [[CPP/Classes/Singleton|Singleton]]

=== Loops ===
* [[CPP/Loops/DoWhile|Do while]]
* [[CPP/Loops/While|While]]
* [[CPP/Loops/For|For]]

=== STL Data Structures ===
*[[CPP/STL/String|String]]
*[[CPP/STL/Vector|Vector]]
*[[CPP/STL/List|List]]
*[[CPP/STL/Set|Set]]
*[[CPP/STL/MultiSet|MultiSet]]
*[[CPP/STL/Map|Map]]
*[[CPP/STL/MultiMap|MultiMap]]
*[[CPP/STL/Pair|Pair]]
*[[CPP/STL/PriorityQueue|Priority queue]]
*[[CPP/STL/Queue|Queue]]
*[[CPP/STL/Tuple|Tuple]]

=== STL Algorithms ===
*[[CPP/STL/RandomShuffle|Random shuffle]]
*[[CPP/STL/Sort|Sort]]

=== Debugging ===
* [[CPP/Debugging/Assert|Assert]]
* [[CPP/Debugging/LineNumbers|LineNumbers]]

=== C++ TR1 ===

*[[CPP/TR1/Regex_Tokenising|Tokenising with RegEx]]

=== C++0x ===
*[[CPP/C++0x/Hash|Hash]]

=== Math ===
*[[CPP/Math/Exponential|Exponential function]]
*[[CPP/Math/MinMax|Min and Max]]
*[[CPP/Math/Trig|Trig functions]]

=== GUI Systems ===
====Qt====

== wxWidgets ==

wxWidgets is GUI toolkit that is used to make nice GUIs using C++ language. wxWidgets is available also as ports in other languages like Python. I tried to say much but I have failed so i copy and paste their Home [http://www.wxwidgets.org/ Home Page] description. Forgive me for failing to tell you

<blockquote style="background-color: lightgrey; border: solid thin grey; padding:5px;">
wxWidgets is a C++ library that lets developers create applications for Windows, OS X, Linux and UNIX on 32-bit
and 64-bit architectures as well as several mobile platforms including Windows Mobile, iPhone SDK and embedded GTK+.It has popular language bindings for Python, Perl, Ruby and many other languages. Unlike other cross-platform toolkits, wxWidgets gives its applications a truly native look and feel because it uses the platform's native API rather than emulating the GUI. It's also extensive, free, open-source and mature. Why not give it a try?
</blockquote>

One thing that this summary didn't tell you is that there are more than GUI classes. There are networking stuffs and Many other whistles and bells. If you feel you need help there is forum and you can buy the book to enhance the speed. Just Go to [http://www.wxwidgets.org/ Home page] and check the links. For more documentations and How-tos, visit [http://wiki.wxwidgets.org/Main_Page Wiki Page]

If you have any questions, you can direct them to [http://forum.wxwidgets.orgwxForum].

Stefano<br />

--[[User:Evstevemd|Evstevemd]] 16:47, 25 June 2010 (UTC)

== Java ==

== Python ==

== Perl ==

Main Page

2010-06-26T14:31:08Z

Bench: /* Strings */

==Welcome to ProgrammingExamples.net!==
This site is intended to provide short, compilable code snippets demonstrating frequently used concepts in several programming languages. Please feel free to modify the existing examples, and add new examples!

=="Do"s and "Don't"s==

=== "Do"s ===
* Try to keep each example as short as possible.
* Try to demonstrate a single concept per example.
* Comment, comment, comment!

=== "Don't"s ===
* Do not treat the wiki as your own personal code dump. Things that are placed here should be useful for many people.

== Coding Standards ==
We don't want to get too carried away here, but below are some guidelines.

* Try to use a sensible indentation scheme.
* Use descriptive variable names.
* Comment, comment, comment!

__TOC__

== C++ ==
* [[CPP/AlphebetizeString|Alphabetize a vector of strings]]
* [[CPP/ZeroPad|Pad a number with zeros]]
* [[CPP/Array|Array]]
* [[CPP/2DArray|2D Array]]
* [[CPP/BinaryIO|Binary input and output]]
* [[CPP/ExecuteLinuxCommand|Execute a linux command]]
* [[CPP/Casting|Casting]]
* [[CPP/CharacterArray|Character array]]
* [[CPP/KeyboardInput|Keyboard input]]
* [[CPP/CommandLineArguments|Command line arguments]]
* [[CPP/DeepCopy|Deep copy]]
* [[CPP/DefaultArguments|Default arguments]]
* [[CPP/Enum|Enum]]
* [[CPP/Exceptions|Exceptions]]
* [[CPP/FunctionPointer|Function pointer]]
* [[CPP/Infinity|Infinity]]
* [[CPP/Logging|Logging]]
* [[CPP/Macros|Macros]]
* [[CPP/Namespaces|Namespaces]]
* [[CPP/NAN|NAN (not a number)]]
* [[CPP/OverloadOperator|Overload operator]]
* [[CPP/ParallelSort|Parallel sort]]
* [[CPP/RandomNumbers|Random numbers]]
* [[CPP/StringStream|StringStream]]
* [[CPP/Struct|Struct]]
* [[CPP/Switch|Switch]]
* [[CPP/Typedef|Typedef]]
* [[CPP/VariableNumberOfArguments|Variable number of function arguments]]

=== I/O ===
* [[CPP/IO/Setw|Column width (setw)]]
* [[CPP/IO/FileInput|File input]]
* [[CPP/IO/FileOutput|File output]]
* [[CPP/IO/ReadingLines|Reading lines from a text file]]

=== Strings ===
* [[CPP/Strings/Compare|Compare strings]]
* [[CPP/Strings/Concatenate|Concatenate]]
* [[CPP/Strings/CountCharacters|Count characters]]
* [[CPP/Strings/Split|Split]]
* [[CPP/Strings/Case_Conversion|Case conversion]]

=== Classes ===
* [[CPP/Classes/ClassTemplate|Class template]]
* [[CPP/Classes/ConstructorInheritance|Constructor inheritance]]
* [[CPP/Classes/InitializationList|Initialization list]]
* [[CPP/Classes/DerivedClass|Derived class]]
* [[CPP/Classes/DownCasting|Down casting]]
* [[CPP/Classes/FriendClass|Friend class]]
* [[CPP/Classes/NestedClasses|Nested classes]]
* [[CPP/Classes/PureVirtualFunction|Pure virtual function]]
* [[CPP/Classes/Singleton|Singleton]]

=== Loops ===
* [[CPP/Loops/DoWhile|Do while]]
* [[CPP/Loops/While|While]]
* [[CPP/Loops/For|For]]

=== STL Data Structures ===
*[[CPP/STL/String|String]]
*[[CPP/STL/Vector|Vector]]
*[[CPP/STL/List|List]]
*[[CPP/STL/Set|Set]]
*[[CPP/STL/MultiSet|MultiSet]]
*[[CPP/STL/Map|Map]]
*[[CPP/STL/MultiMap|MultiMap]]
*[[CPP/STL/Pair|Pair]]
*[[CPP/STL/PriorityQueue|Priority queue]]
*[[CPP/STL/Queue|Queue]]
*[[CPP/STL/Tuple|Tuple]]

=== STL Algorithms ===
*[[CPP/STL/RandomShuffle|Random shuffle]]
*[[CPP/STL/Sort|Sort]]

=== Debugging ===
* [[CPP/Debugging/Assert|Assert]]
* [[CPP/Debugging/LineNumbers|LineNumbers]]

=== C++0x ===
*[[CPP/C++0x/Hash|Hash]]

=== Math ===
*[[CPP/Math/Exponential|Exponential function]]
*[[CPP/Math/MinMax|Min and Max]]
*[[CPP/Math/Trig|Trig functions]]

=== GUI Systems ===
====Qt====
== wxWidgets ==

wxWidgets is GUI toolkit that is used to make nice GUIs using C++ language. wxWidgets is available also as ports in other languages like Python. I tried to say much but I have failed so i copy and paste their Home [http://www.wxwidgets.org/ Home Page] description. Forgive me for failing to tell you

<blockquote style="background-color: lightgrey; border: solid thin grey; padding:5px;">
wxWidgets is a C++ library that lets developers create applications for Windows, OS X, Linux and UNIX on 32-bit
and 64-bit architectures as well as several mobile platforms including Windows Mobile, iPhone SDK and embedded GTK+.It has popular language bindings for Python, Perl, Ruby and many other languages. Unlike other cross-platform toolkits, wxWidgets gives its applications a truly native look and feel because it uses the platform's native API rather than emulating the GUI. It's also extensive, free, open-source and mature. Why not give it a try?
</blockquote>

One thing that this summary didn't tell you is that there are more than GUI classes. There are networking stuffs and Many other whistles and bells. If you feel you need help there is forum and you can buy the book to enhance the speed. Just Go to [http://www.wxwidgets.org/ Home page] and check the links. For more documentations and How-tos, visit [http://wiki.wxwidgets.org/Main_Page Wiki Page]

If you have any questions, you can direct them to [http://forum.wxwidgets.orgwxForum].

Stefano<br />

--[[User:Evstevemd|Evstevemd]] 16:47, 25 June 2010 (UTC)

== Java ==

== Python ==

== Perl ==

CPP/Strings/Case Conversion

2010-06-26T14:30:17Z

Bench:

<source lang="cpp">
#include <string>
#include <algorithm> // transform
#include <functional> // ptr_fun
#include <cctype> // toupper, tolower
#include <iostream>

int main()
{
std::string clive = "Clive Cherishes Capitals",
lewis = "Lewis LOVES Lowercase";

// transform each character in 'clive' with 'toupper'
std::transform(clive.begin(), clive.end(), clive.begin(),
std::ptr_fun<int,int>(std::toupper) );

// transform each character in 'lewis' with 'tolower'
std::transform(lewis.begin(), lewis.end(), lewis.begin(),
std::ptr_fun<int,int>(std::tolower) );

std::cout << clive << std::endl;
std::cout << lewis << std::endl;
}
</source>

CPP/Strings/Case Conversion

2010-06-26T14:29:43Z

Bench: C++ upper/lower case string conversion

#include <string>
#include <algorithm> // transform
#include <functional> // ptr_fun
#include <cctype> // toupper, tolower
#include <iostream>

int main()
{
std::string clive = "Clive Cherishes Capitals",
lewis = "Lewis LOVES Lowercase";

// transform each character in 'clive' with 'toupper'
std::transform(clive.begin(), clive.end(), clive.begin(),
std::ptr_fun<int,int>(std::toupper) );

// transform each character in 'lewis' with 'tolower'
std::transform(lewis.begin(), lewis.end(), lewis.begin(),
std::ptr_fun<int,int>(std::tolower) );

std::cout << clive << std::endl;
std::cout << lewis << std::endl;
}