C++ Basics (Part 1)

Structure of a C++ Program

Building and Running a C++ Program

Starts with source code, like the first sample program
  1. Pre-processing
  2. Compiling
  3. Linking
  4. Run it!


Variables are used to store data. Every C++ variable has a: When a program is compiled, a symbol table is created, mapping each variable name to its type, size, and address


Identifiers are the names for things (variables, functions, etc) in the language. Some identifiers are built-in, and others can be created by the programmer.

Style-conventions (for indentifiers)

Declaring Variables

Atomic Data Types

Atomic data types are the built-in types defined by the C++ language


This program will print the number of bytes used by each type - sizes may vary from system to system

Initializing Variables

More Declaration Examples, using various types

Constant Variables

(Woohoo! An oxymoron!)

Symbolic Constants (an alternative)

Questions to consider

Other Basic Code Elements


Literals are also constants. They are literal values written in code.

Escape Sequences



Comments are for documenting programs. They are ignored by the compiler.

Input and Output with streams in C++:

In C++ we use do I/O with "stream objects", which are tied to various input/output devices.

Some pre-defined stream objects

These stream objects are defined in the iostream library

To use these streams, we need to include the iostream library into our programs.

 #include <iostream>
 using namespace std;
The using statement tells the compiler that all uses of these names (cout, cin, etc) will come from the "standard" namespace.

Using Input and Output Streams

Some special formatting for decimal numbers

Some simple program examples