Data Types
Understanding data types is fundamental to programming. Data types define the kind of value a variable can hold and the operations that can be performed on it. In our system, we support a range of primitive and complex data types to represent diverse information.
Primitive Data Types
These are the most basic types of data. They are immutable and directly represent single values.
Numeric Types
Used for representing numbers. We distinguish between integers and floating-point numbers.
| Type | Description | Range/Precision | Example |
|---|---|---|---|
Integer |
Whole numbers, positive or negative, without decimals. | Typically 32-bit or 64-bit, depending on the architecture. | 10, -500, 0 |
Float |
Numbers with a decimal point. | IEEE 754 single-precision. | 3.14, -0.001, 1.0 |
Double |
Numbers with a decimal point, offering higher precision than Float. |
IEEE 754 double-precision. | 1.23456789012345, -2.71828 |
Boolean Type
Represents truth values.
| Type | Description | Values | Example |
|---|---|---|---|
Boolean |
Indicates truth or falsehood. | True, False |
True, False |
Character Type
Represents a single character.
| Type | Description | Example |
|---|---|---|
Char |
A single character, typically enclosed in single quotes. | 'A', 'z', '7', '$' |
String Type
Represents a sequence of characters.
| Type | Description | Example |
|---|---|---|
String |
A sequence of characters, typically enclosed in double quotes. | "Hello, World!", "MSDN", "" (empty string) |
Complex Data Types
These types are built from primitive types and can represent more structured and complex data.
Array Type
An ordered collection of elements of the same data type.
Arrays are zero-indexed, meaning the first element is at index 0.
// Example of an integer array
Integer[] numbers = {10, 20, 30, 40, 50};
// Accessing an element
Integer firstNumber = numbers[0]; // firstNumber will be 10
Structure (Struct) Type
A composite data type that groups together variables of different data types under a single name. Useful for representing records or objects with named fields.
// Example of a User struct
struct User {
String username;
Integer userId;
Boolean isActive;
};
// Creating an instance of User
User newUser;
newUser.username = "johndoe";
newUser.userId = 101;
newUser.isActive = True;
// Accessing a field
String userName = newUser.username; // userName will be "johndoe"
Object Type
Represents instances of classes, which can encapsulate data (attributes) and behavior (methods). Objects are the cornerstone of object-oriented programming.
Detailed explanation of objects and classes can be found in the "Object-Oriented Programming" section.
Type Conversion
Sometimes, you may need to convert a value from one data type to another. This is known as type conversion or type casting.
- Implicit Conversion: The compiler automatically converts data types, typically from a 'smaller' to a 'larger' type (e.g.,
IntegertoFloat). - Explicit Conversion: You, the programmer, must explicitly instruct the system to convert data types, often necessary when converting from a 'larger' to a 'smaller' type or between incompatible types. This can sometimes lead to data loss or errors if not handled carefully.
Example of Explicit Conversion
Float pi = 3.14159;
Integer roundedPi = Integer(pi); // Explicitly convert Float to Integer
String numberStr = "123";
Integer numberInt = Integer(numberStr); // Convert String to Integer
Careful consideration of data types and their conversions is crucial for writing robust and efficient code.