Primitive Data Types

In C, primitive data types are the fundamental building blocks used to represent data. They are predefined by the language and have a fixed size in memory, although this size can vary depending on the system architecture (e.g., 32-bit vs. 64-bit). The most common primitive data type is `int`, used to store whole numbers (integers) like -10, 0, and 42. It is typically the most efficient data type for integer arithmetic on a given processor. For storing single characters, like 'a', '$', or '7', we use the `char` data type. Internally, `char` is stored as an integer value corresponding to its ASCII code. For numbers with fractional parts, C provides two main types: `float` and `double`. `float` represents single-precision floating-point numbers, offering about 7 digits of precision. `double` represents double-precision floating-point numbers, providing roughly 15 digits of precision, making it more suitable for calculations that require high accuracy. These basic types can be modified with qualifiers to alter their properties. The `signed` and `unsigned` qualifiers can be applied to `int` and `char`. A `signed` type can hold both positive and negative values, while an `unsigned` type can only hold non-negative values, effectively doubling its maximum positive range. The `short` and `long` qualifiers can be applied to `int`. `short int` may use less memory than a standard `int`, while `long int` (or just `long`) provides a larger range of values. Similarly, `long double` can provide even greater precision than a `double`. Choosing the right data type is crucial for memory efficiency and preventing data overflow errors.