Beginner's Guide: An Introduction to C++ Variables and Data Types

In C++, data types and variables are fundamental to programming. Data types "label" data, allowing the computer to clearly understand how to store and process it (e.g., integers, decimals, characters). Variables are containers for storing data, requiring a specified type (e.g., `int`) and a name (e.g., `age`). Common data types include: integer types (`int` occupies 4 bytes; `long`/`long long` have larger ranges); floating-point types (`float` is single-precision with 4 bytes, `double` is double-precision with 8 bytes and higher precision); character type `char` (stores a single character in 1 byte); and boolean type `bool` (only `true`/`false`, used for conditional judgments). Variables must be declared with their type specified. Initialization upon definition is recommended (uninitialized values are random). Naming rules: letters, numbers, and underscores; cannot start with a number or use keywords; case-sensitive; and names should be meaningful. Examples: Define `int age = 20`, `double height = 1.75`, etc., and output their values. Practice is key to mastering this, with emphasis on choosing the right type and using proper naming.