Preface

Computers are some of the most versatile tools that we have available. They are capable of performing stunning feats of computation, they allow information to be exchanged easily regardless of location, they simplify many every-day tasks, and they allow us to automate many processes that would be tedious or boring to perform otherwise. However, computers are not "intelligent" as we are. They have to be told in no uncertain terms exactly what they're supposed to do, and their native languages are quite unlike anything we speak. Thus, there's a formidable language barrier between a person who wishes a computer to do something, and the computer that does not know what it's supposed to do. So far, computers cannot figure out what they are supposed to do on their own, and thus they rely on programs which we create, which are sets of instructions that the computer can understand and follow.

The Features of C++ as a Language

• ...is an open ISO-standardized language.
  
For a time, C++ had no official standard and was maintained by a de-facto standard, however since 1998, C++ is standardized by a committee of the ISO. Their page may be accessed here.
• ...is a compiled language.
  
C++ compiles directly to a machine's native code, allowing it to be one of the fastest languages in the world, if optimized.
• ...is a strongly-typed unsafe language.
  
C++ is a language that expects the programmer to know what he or she is doing, but allows for incredible amounts of control as a result.
• ...supports both manifest and inferred typing.
  
As of the latest C++ standard, C++ supports both manifest and inferred typing, allowing flexibility and a means of avoiding verbosity where desired.
• ...supports both static and dynamic type checking.
  
C++ allows type conversions to be checked either at compile-time or at run-time, again offering another degree of flexibility. Most C++ type checking is, however, static.
• ...offers many paradigm choices.
  
C++ offers remarkable support for procedural, generic, and object-oriented programming paradigms, with many other paradigms being possible as well.
• ...is portable.
  
As one of the most frequently used languages in the world and as an open language, C++ has a wide range of compilers that run on many different platforms that support it. Code that exclusively uses C++'s standard library will run on many platforms with few to no changes..
• ...is upwards compatible with C
  
C++, being a language that directly builds off C, is compatible with almost all C code. C++ can use C libraries with few to no modifications of the C library code.
• ...has incredible library support.
  
A search for "library" on the popular project-management website SourceForge will yield over 3000 results for C++ libraries. A link to the results of the search may be found here.




Identifiers

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A valid identifier is a sequence of one or more letters, digits or underscore characters (_). Neither spaces nor punctuation marks or symbols can be part of an identifier. Only letters, digits and single underscore characters are valid. In addition, variable identifiers always have to begin with a letter. They can also begin with an underline character (_ ), but in some cases these may be reserved for compiler specific keywords or external identifiers, as well as identifiers containing two successive underscore characters anywhere. In no case can they begin with a digit.

Another rule that you have to consider when inventing your own identifiers is that they cannot match any keyword of the C++ language nor your compiler's specific ones, which are reserved keywords. The standard reserved keywords are:
asm, auto, bool, break, case, catch, char, class, const, const_cast, continue, default, delete, do, double, dynamic_cast, else, enum, explicit, export, extern, false, float, for, friend, goto, if, inline, int, long, mutable, namespace, new, operator, private, protected, public, register, reinterpret_cast, return, short, signed, sizeof, static, static_cast, struct, switch, template, this, throw, true, try, typedef, typeid, typename, union, unsigned, using, virtual, void, volatile, wchar_t, while

Additionally, alternative representations for some operators cannot be used as identifiers since they are reserved words under some circumstances:
and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor, xor_eq

Very important: The C++ language is a "case sensitive" language. That means that an identifier written in capital letters is not equivalent to another one with the same name but written in small letters. Thus, for example, the RESULT variable is not the same as the result variable or the Result variable. These are three different variable identifiers.




Fundamental Data Types

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When programming, we store the variables in our computer's memory, but the computer has to know what kind of data we want to store in them, since it is not going to occupy the same amount of memory to store a simple number than to store a single letter or a large number, and they are not going to be interpreted the same way.

The memory in our computers is organized in bytes. A byte is the minimum amount of memory that we can manage in C++. A byte can store a relatively small amount of data: one single character or a small integer (generally an integer between 0 and 255). In addition, the computer can manipulate more complex data types that come from grouping several bytes, such as long numbers or non-integer numbers.

Next you have a summary of the basic fundamental data types in C++, as well as the range of values that can be represented with each one:



Here is a Sample Program:




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