Dart Data Types

Dart is a statically typed language with a rich set of built-in data types. Understanding these types is crucial for efficient programming and type safety.

Basic Data Types

Numbers

Dart provides two number types:

• int: For whole numbers
• double: For floating-point numbers

Example:

int age = 30;
double price = 19.99;
    

Strings

Text is represented using the String type. Dart supports both single and double quotes for string literals.

Example:

String name = 'John Doe';
String message = "Hello, World!";
    

Booleans

The bool type represents true or false values.

Example:

bool isActive = true;
bool hasPermission = false;
    

Collection Types

Lists

Dart uses List for ordered collections of objects. Lists are similar to arrays in other languages.

Example:

List<String> fruits = ['apple', 'banana', 'orange'];
    

Sets

A Set is an unordered collection of unique items.

Example:

Set<int> numbers = {1, 2, 3, 4, 5};
    

Maps

Dart's Map type represents key-value pairs.

Example:

Map<String, int> ages = {
  'John': 30,
  'Jane': 25,
  'Bob': 40
};
    

Special Types

Dynamic

The dynamic type allows variables to hold values of any type.

Null Safety

Dart supports Null Safety, which helps prevent null reference errors. Use the ? operator to declare nullable types.

Example:

String? nullableName;
int nonNullableAge = 25;
    

Best Practices

• Use specific types when possible for better type safety and code clarity.
• Leverage Dart's type inference to reduce verbosity while maintaining type safety.
• Consider using Dart Generics for more flexible and reusable code.
• Be mindful of Type Promotion when working with nullable types.

Conclusion

Understanding Dart's data types is fundamental to writing efficient and error-free code. As you progress, explore more advanced topics like Dart Classes and Dart Interfaces to fully leverage Dart's type system.