What are the characteristics of basic data types?

Basic data types have the characteristics of fixed size, fixed value range, immutability, direct access to memory, default value, operation rules, occupied storage space, speed, special functions and conversions. Detailed introduction: 1. Fixed size. Basic data types have a fixed size when declared, which means that the storage space of each basic data type is the same under any circumstances and will not change due to the value of the variable; 2. Fixed value range, each basic data type has a fixed value range; 3. Immutability, basic data types are immutable, etc.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

Basic data types are the most basic data structures in computer programming languages. They include integer types, floating point types, character types, Boolean types, etc. These basic data types have the following characteristics:

1. Fixed size: Basic data types have a fixed size when declared, such as the number of bytes or bits. This means that the storage space of each basic data type is the same in any case and does not change due to the value of the variable.

2. Fixed value range: Each basic data type has a fixed value range. For example, the value range of the integer type may be from -2^31 to 2^31-1, and the value range of the floating point type may be from 1.2E-38 to 3.4E 38. These ranges vary from programming language to programming language, but they are fixed and do not change depending on the value of the variable.

3. Immutability: Basic data types are immutable. Once the type of a variable is declared, it cannot be changed. This means that the values ​​of variables of basic data types cannot be modified while the program is running.

4. Direct access to memory: Basic data types are usually stored directly in memory, which means that accessing variables of these types is faster than accessing complex data types such as arrays or objects.

5. Default value: Most programming languages ​​provide default values ​​for basic data types. For example, the default value of an uninitialized integer variable might be 0, and the default value of an uninitialized floating-point variable might be NaN (not a number).

6. Operation rules: Basic data types follow specific operation rules. For example, integer types can be added, subtracted, multiplied, divided, etc., but the result is still an integer. The floating-point number type can perform operations such as addition, subtraction, multiplication, and division, but the result is a floating-point number.

7. Storage space occupied: The storage space occupied by basic data types depends on their size and number of bytes. For example, an integer type variable may occupy 4 bytes (32 bits), while a character type variable may occupy only 1 byte.

8. Speed: The operation speed of basic data types is usually faster than that of complex data types. Because they are stored directly in memory, accessing and manipulating variables of these types is faster than accessing and manipulating complex data types such as arrays or objects.

9. Special functions: Basic data types usually have some special functions and methods that can be used. For example, for string types, you can use methods such as string concatenation ( ) or interception (substr). For numeric types, you can use mathematical functions (such as sin, cos, sqrt, etc.).

10. Conversion: Conversion between basic data types usually involves rounding or rounding operations. For example, when converting an integer to a floating point number, the fractional part equal to 0 is truncated. Conversely, when converting a floating point number to an integer, the fractional part is discarded. In addition, some programming languages ​​allow other types of conversions, such as Boolean to integer, etc.

In short, basic data types are one of the most basic data structures in computer programming languages. They have fixed size and value range, immutability, direct access to memory and other characteristics. Mastering the concepts and usage of basic data types is one of the foundations of learning programming.

The above is the detailed content of What are the characteristics of basic data types?. For more information, please follow other related articles on the PHP Chinese website!