diff options
| -rw-r--r-- | c++.html.markdown | 56 |
1 files changed, 41 insertions, 15 deletions
diff --git a/c++.html.markdown b/c++.html.markdown index dbca751f..50de5eff 100644 --- a/c++.html.markdown +++ b/c++.html.markdown @@ -7,12 +7,14 @@ contributors: lang: en --- -C++ was designed as a systems programming language that +C++ is a systems programming language that, +[according to its inventor Bjarne Stroustrup](http://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2014/Keynote), +was designed to -- is a "better C" -- supports data abstraction -- supports object-oriented programming -- supports generic programming +- be a "better C" +- support data abstraction +- support object-oriented programming +- support generic programming Though its syntax can be more difficult or complex than newer languages, it is widely used because it compiles to native instructions that can be @@ -32,9 +34,21 @@ one of the most widely-used programming languages. // A main() function in C++ should return an int, // though void main() is accepted by most compilers (gcc, clang, etc.) -int main() // or int main(int argc, char** argv) +// This value serves as the program's exit status. +// See http://en.wikipedia.org/wiki/Exit_status for more information. +int main(int argc, char** argv) { - return 0; // Can also end without return statement + // Command line arguments are passed in by argc and argv in the same way + // they are in C. + // argc indicates the number of arguments, + // and argv is an array of C-style strings (char*) + // representing the arguments. + // The first argument is the name by which the program was called. + // argc and argv can be omitted if you do not care about arguments, + // giving the function signature of int main() + + // An exit status of 0 indicates success. + return 0; } // In C++, character literals are one byte. @@ -82,21 +96,33 @@ void print(int myInt) int main() { - printing("Hello"); // Resolves to void print(const char*) - printing(15); // Resolves to void print(int) + print("Hello"); // Resolves to void print(const char*) + print(15); // Resolves to void print(int) } ///////////////////////////// // Default function arguments ///////////////////////////// -void two_ints(int a = 1, int b = 4); +// You can provide default arguments for a function +// if they are not provided by the caller. + +void doSomethingWithInts(int a = 1, int b = 4) +{ + // Do something with the ints here +} int main() { - two_ints(); // a = 1, b = 4 - two_ints(20); // a = 20, b = 4 - two_ints(20, 5); // a = 20, b = 5 + doSomethingWithInts(); // a = 1, b = 4 + doSomethingWithInts(20); // a = 20, b = 4 + doSomethingWithInts(20, 5); // a = 20, b = 5 +} + +// Default arguments must be at the end of the arguments list. + +void invalidDeclaration(int a = 1, int b) // Error! +{ } @@ -106,7 +132,7 @@ int main() // Namespaces provide separate scopes for variable, function, // and other declarations. -// Namespaces can be nested +// Namespaces can be nested. namespace First { namespace Nested { @@ -362,7 +388,7 @@ public: Point() { }; // The following syntax is known as an initialization list - // and is the proper way to initialize class member values + // and is the proper way to initialize class member values Point (double a, double b) : x(a), y(b) |