Merge pull request #757 from xksteven/master

[c++/en] Created c++ tutorial

c++.html.markdown

@@ -0,0 +1,349 @@
+---
+language: c++
+filename: learncpp.cpp
+contributors:
+    - ["Steven Basart", "http://github.com/xksteven"]
+lang: en
+---
+
+I am writing this to highlight the differences and 
+additions that C++ has with respect to C. My 
+suggestion would be to follow the C tutorial first
+then look here for the additions and differences.
+
+```c++
+///////////////////////////////////////   
+// C++ differences   
+///////////////////////////////////////  
+
+
+//In C++   
+//cannot use void main()   
+int main() { //or int main(int argc, char **argv)   
+    //cannot end with return;   
+    return 0;   
+    //Can also end without return statement   
+}   
+   
+//In C++  
+/*    
+  //This could lead to compiler errors and is discouraged    
+  //#if 0 #endif pairs are encouraged instead   
+*/   
+   
+//In C++    
+sizeof(10) //Typically 4   
+sizeof('c') == 1    
+
+//In C   
+sizeof('c') == sizeof(10) //true chars are passed as ints   
+
+
+//In C++ strict prototyping   
+void func(); //function which accepts no arguments   
+
+//In C   
+void func(); //function which may accept arguments    
+
+
+//In C++   
+for(int i = 0; i < 10; i++) {;}   
+//In C must int i must be declared before   
+
+
+//C++ Supports Function overloading   
+//Provided each function takes different   
+//parameters    
+
+void printing(char const *myString)    
+{printf("String %s\n",myString);} //Hello   
+
+void printing(int myInt)    
+{printf("My int is %d",myInt);} //15   
+
+int main ()    
+{   
+    printing("Hello");   
+    printing(15);   
+}   
+   
+
+
+//C++ Default Function Arguments   
+void two_ints(int a = 1, int b = 4);   
+
+int main()   
+{    
+    two_ints();            // arguments:  1, 4   
+    two_ints(20);          // arguments: 20, 4   
+    two_ints(20, 5);       // arguments: 20, 5   
+}   
+
+
+//C++ added the nullptr which is different from 0   
+int *ip = nullptr;      // OK   
+int value = nullptr;    // error: value is no pointer  
+
+
+///////////////////////////////////////   
+// C++ Additions ontop of C    
+///////////////////////////////////////   
+
+
+///////////////////////////////////////   
+// C++ Namespace   
+///////////////////////////////////////   
+
+//Namespaces allow you to define your own    
+//functions and variables for use    
+
+// Use '::' to change variable (or function) scope   
+// Putting '::' before a function or variable will   
+// reference a global scope    
+
+// This allows you to make normal c library calls   
+// std is for standard library    
+using namespace std;   
+
+#include <stdio.h>    
+
+int counter = 50;                // global variable    
+
+int main()   
+{   
+    for (int counter = 1;        // this refers to the   
+    counter < 2;                 // local variable   
+    counter++)   
+    {   
+        printf("Global var %d local var %d\n",    
+            ::counter,           // global variable    
+            counter);            // local variable    
+        // => Global var 50 local var 1   
+    }   
+}   
+
+// Namespaces can be nested   
+
+
+namespace myFirstNameSpace   
+{   
+    namespace myInnerSoul   
+    {   
+        cos(int x)   
+        {   
+            printf("My inner soul was made to program.");   
+	}   
+    }   
+}   
+
+namespace anotherNameSpace  
+{   
+    cos(int x) {;} //does nothing   
+}   
+   
+int main()   
+{   
+    //Specify the full path because main is outside of both namespaces.    
+    //Will print out My inner soul was made to program.    
+    myFirstNameSpace::myInnerSoul::cos(60);   
+}   
+
+
+///////////////////////////////////////   
+// C++ Strings   
+///////////////////////////////////////   
+
+//Strings in C++ are Objects and have many functions  
+myString = "Hello";   
+myOtherString = " World";   
+
+myString + myOtherString; // => "Hello World"    
+
+myString + ' You'; // => "Hello You"   
+
+myString != myOtherString; //True   
+
+//An example of a string method   
+myString.append(" Dog"); // => "Hello Dog"   
+
+
+///////////////////////////////////////   
+// C++ Input Output   
+///////////////////////////////////////   
+
+//C++ input and output streams   
+//cin, cout, cerr, << is insertion and >> is extraction operator   
+#include <iostream>   
+
+using namespace std;   
+
+int main()   
+{   
+
+   int myInt;   
+    
+   //Prints to stdout (or terminal/screen)   
+   cout << "Enter your fav number:\n"   
+   //Takes in input   
+   cin >> myInt;   
+
+   //cout can also be formatted   
+   cout << "Your fav number is " << myInt << "\n"   
+   //Your fav number is ##  
+
+   cerr << "Used for error messages"   
+}   
+
+
+///////////////////////////////////////   
+// C++ Classes   
+///////////////////////////////////////
+
+
+//First example of classes   
+#include <iostream>   
+
+//define a class    
+class Doggie   
+{   
+    std::string name;   
+    int         weight;   
+
+   // These are only the declarations   
+   //Can also have private and protected   
+   public:     
+       //The public methods (can also include variables)   
+
+   // Default constructor   
+   Doggie();   
+
+   void setName(std::string dogsName);   
+   void setWeight(int dogsWeight);    
+   void printDog();   
+
+   //Can define functions within class declaration too   
+   void dogBark() {std::cout << "Bark Bark\n"}   
+
+   //Destructors are methods that free the allocated space   
+   ~doggieDestructor();   
+   //if no destructor compiler defines the trivial destructor   
+
+//Classes are similar to structs and must close the } with ;    
+};   
+
+// This is the implementation of the class methods   
+// Also called the definition   
+void Doggie::Doggie () {   
+    std::cout << "A doggie is born. Woof!\n";   
+}   
+ 
+void Doggie::setName (std::string doggie_name) {    
+    name = doggie_name;   
+}   
+
+void Doggie::setWeight (int doggie_weight) {   
+    weight = doggie_weight;   
+}   
+
+void Doggie::printDog () {   
+    std::cout << "Dog is " << name << " weighs" << weight << "\n";    
+}   
+
+void Doggie::~doggieDestructor () {   
+    delete[] name;   
+    delete weight;    
+}   
+
+int main () {    
+  Doggie deedee; // prints out a doggie is born. Woof!   
+  deedee.setName ("Barkley");    
+  deedee.setWeight(1000000);   
+  deedee.printDog;   
+  //prints => Dog is Barkley weighs 1000000    
+  return 0;   
+}   
+
+
+//C++ Class inheritance   
+
+class German_Sheperd   
+{
+   //This class now inherits everything public and protected from Doggie class   
+   Doggie      d_dog;   
+
+   //Good practice to put d_ in front of datatypes in classes   
+   std::string d_type;   
+
+   public:  
+      void dogType() {d_type = "German Sheperd";}   
+};   
+
+
+
+///////////////////////////////////////   
+// C++ Exception Handling   
+///////////////////////////////////////    
+
+try {   
+   throw 12.25;  // throws a double no handler declared   
+} catch (int errorNum)   
+{   
+  std::cout << "I caught an int " << errorNum << "\n";   
+//default catcher   
+} catch (...)   
+{   
+    std::cout << "I got an error. Not sure what but I can pass it up.";   
+    throw;   
+}   
+
+
+///////////////////////////////////////    
+// C++ Operator Overloading   
+///////////////////////////////////////   
+
+// In C++ you can overload operators such as +, -, new, etc.   
+
+#include <iostream>   
+using namespace std;   
+
+class Vector {   
+    public:   
+        double x,y;   
+        Vector () {};   
+        Vector (double a, double b) : x(a), y(b) {}   
+        Vector operator + (const CVector&);   
+        Vector operator += (const CVector&);   
+};   
+ 
+Vector Vector::operator+ (const Vector& rhs)    
+{   
+    Vector temp;   
+    temp.x = x + rhs.x;   
+    temp.y = y + rhs.y;   
+    return temp;   
+}   
+
+Vector Vector::operator+= (const Vector& rhs)   
+{   
+    x += rhs.x;   
+    y += rhs.y;   
+    return *this;   
+}    
+
+int main () {   
+    Vector up (0,1);   
+    Vector right (1,0);   
+    Vector result;    
+    // This calls the Vector + operator   
+    // Vector up calls the + (function) with right as its paramater   
+    result = up + right;   
+    // prints out => Result is upright (1,1)   
+    cout << "Result is upright (" << result.x << ',' << result.y << ")\n";   
+    return 0;   
+}
+
+```
+Futher Reading   
+
+for more resources see: http://www.icce.rug.nl/documents/cplusplus/   
+for other reference material: http://www.cplusplus.com/doc/tutorial/