Dart Data Types

Understanding different types of data in Dart

📊 What are Dart Data Types?

Dart data types define what kind of values variables can store. Dart supports numbers, strings, booleans, lists, and more to handle different data efficiently. 


// Different data types in Dart
int age = 25;
String name = 'John';
bool isStudent = true;

Common Dart Data Types

🔢

Numbers

int and double for numeric values 

int count = 10;
double price = 99.99;
📝

Strings

Text data using single or double quotes 

String message = 'Hello World';
String name = "Alice";
✅

Booleans

True or false values 

bool isActive = true;
bool isComplete = false;
📋

Lists

Collections of items 

List fruits = ['apple', 'banana'];
List numbers = [1, 2, 3];

🔹 Number Types

Dart has two main number types: 

// Integer numbers
int age = 25;
int temperature = -10;

// Decimal numbers  
double height = 5.9;
double pi = 3.14159;

// num can be either int or double
num score = 85;
num average = 87.5;

Output:

age: 25

height: 5.9

score: 85

🔹 String Type

Strings store text data: 

// Single quotes
String firstName = 'John';

// Double quotes
String lastName = "Doe";

// Multi-line strings
String address = '''
123 Main Street
New York, NY
''';

// String interpolation
String fullName = '$firstName $lastName';
print(fullName); // John Doe

Output:

John Doe

🔹 Boolean Type

Booleans represent true/false values: 

bool isLoggedIn = true;
bool hasPermission = false;

// Using in conditions
if (isLoggedIn) {
  print('Welcome back!');
}

// Boolean operations
bool canAccess = isLoggedIn && hasPermission;

Output:

Welcome back!

🔹 Collection Types

Store multiple values together:

🔸 Lists (Arrays) 

// List of strings
List colors = ['red', 'green', 'blue'];

// List of numbers
List scores = [85, 92, 78];

// Adding items
colors.add('yellow');
print(colors); // [red, green, blue, yellow]

🔸 Maps (Key-Value pairs) 

// Map with string keys
Map ages = {
  'Alice': 25,
  'Bob': 30,
  'Charlie': 35
};

print(ages['Alice']); // 25

Output:

[red, green, blue, yellow]

25

🧠 Test Your Knowledge

Which data type would you use to store a person's age?