Introduction
C++ is a powerful and flexible programming language that supports procedural, object-oriented, and generic programming. It provides a rich set of features including classes, templates, exception handling, and a strong type system. Understanding the basic syntax and data types is fundamental before diving into more advanced topics. The structure and syntax of a C++ program determine how the compiler interprets and executes the code. Data types define the type of data a variable can hold and how much memory it occupies.
Structure of a C++ Program
A basic C++ program generally includes the following components:
- Preprocessor directives
- Namespace declaration
- The main() function
- Statements inside the main function
- Return statement indicating the exit status
General Syntax:
#include using namespace std;
int main() {
// Statements
return 0; }
Example:
#include using namespace std;
int main() {
cout << “Hello, World!” << endl;
return 0; }
Tokens in C++
Tokens are the smallest individual units in a C++ program. The compiler breaks the program into tokens for processing. C++ has the following types of tokens:
- Keywords: Reserved words with special meaning
e.g., int, return, while
- Identifiers: Names given to variables, functions, arrays, etc.
e.g., age, totalSum
- Constants: Fixed values that do not change during execution
e.g., 5, ‘A’, 3.14
- Operators: Symbols that perform operations on variables and values
e.g., +, -, *, /
- Separators: Symbols used to structure code
e.g., ; { } ( )