C++ Programming Basics

Study Notes

C++ Programming Basics

Function: A collection of statements that performs a specific task.
Syntax: The rules that govern the structure and order of elements in C++ code.
Programming Language: A set of rules, symbols, and special words used to communicate with a computer.
Semantic Rule: The meaning or interpretation of an instruction in C++.
Comments: Notes in code that are ignored by the compiler but provide human-readable explanations.
- Single-line comments begin with //
- Multi-line comments are enclosed between /* and */
Special Symbols: Used in C++ code for various purposes:
- + (addition), - (subtraction), * (multiplication), / (division), % (modulus), = (assignment)
- ?, -, , and ; (semicolon)
Reserved Words (Keywords): Words with predefined meanings in C++ that cannot be used as identifiers.
- Examples: int, float, double, char, const, void, return.
Identifiers: Names given to elements like variables, constants, and functions in C++ code.
- Start with a letter or underscore (_).
- Can only include letters, digits, and underscores.
- Can include upper and lowercase letters (case-sensitive).
- cin and cout are predefined identifiers for input and output streams.
Whitespaces: Used in code for readability and separate keywords, identifiers, and special symbols.
- Include spaces, tabs, and newline characters.
Data Types: Sets of values and operations that define the type of information.
Simple Data Types: Categorized into three groups:
- Integral (integers): char, short, int, long, bool, unsigned char, unsigned short, unsigned int, unsigned long.
  - Integers are numbers without a decimal point.
- Floating-point (decimal numbers): float, double.
- Enumeration type: User-defined data types with a fixed set of named integer values.
int Data Type: Represents whole numbers.
- Examples: -6728, 0, 78, +763.
- Positive integers do not require a + sign.
- Commas are not used within integers (used for lists).
bool Data Type: Represents logical values (true or false).
- bool, true, and false are reserved words.
char Data Type: Represents single characters.
- Enclosed in single quotes (').
- Examples: 'A', 'a', '0', '*', '+'.
Floating-Point Data Types: Used for representing real numbers (numbers with decimal points).
- float: Represents single-precision floating-point numbers.
- double: Represents double-precision floating-point numbers.
Precision: The maximum number of significant digits that can be represented.
- float has lower precision than double.
Arithmetic Operators: Used for mathematical operations.
- + (addition), - (subtraction), * (multiplication), / (division), % (modulus).
- Can be unary (operating on a single operand) or binary (operating on two operands).
Operator Precedence: The order in which operators are evaluated in an expression.
- Parentheses have the highest precedence.
- Multiplication, division, and modulus have the same precedence and are evaluated before addition and subtraction.
- Operators at the same level are evaluated from left to right (associativity).
Expressions: Combinations of operators, operands, and function calls.
- Integral expressions: All operands are integers.
- Floating-point expressions: All operands are floating-point numbers.
Mixed Expressions: Contain operands of different data types (both integers and floating-point numbers).
- Integer operands are converted to floating-point during evaluation.
- The result is always a floating-point number.
Type conversion (Casting): Explicitly changing the data type of an expression.
- static_cast(expression): The most common type conversion operator in C++.
string Type: Used to represent sequences of characters (text).
- Enclosed in double quotes (").
- Null string: An empty string with no characters.
- Each character in a string has a position starting at 0.
- The length of a string is the number of characters.
Assignment Statement: Used to assign a value to a variable.
- variable = expression;
- The = symbol is the assignment operator.
Declaring and Initializing Variables: Declaring a variable tells the compiler the data type and name.
- Variables can be initialized during declaration or later using assignment statements.
- It is essential to initialize variables before using them.