Dart Core Library
Essential built-in functionality for Dart programming
🎯 What is Dart Core Library?
Dart Core Library provides fundamental classes and functions for all Dart programs. It includes basic data types, collections, and essential utilities that form the foundation of Dart programming.
// Core library is imported automatically
void main() {
String message = 'Hello Core!';
List numbers = [1, 2, 3];
print('$message Numbers: $numbers');
}
Output:
Hello Core! Numbers: [1, 2, 3]
Core Data Types
String
Text manipulation and operations
String name = 'Dart';
print(name.toUpperCase());
print(name.length);Numbers
int and double for numeric values
int age = 25;
double price = 99.99;
print(age + price.round());bool
Boolean true/false values
bool isActive = true;
bool isEmpty = false;
print(isActive && !isEmpty);Collections
List, Set, and Map data structures
List fruits = ['apple', 'banana'];
Map scores = {'Alice': 95}; 🔹 String Operations
Common string manipulations:
void main() {
String text = 'Hello Dart World';
// Basic operations
print('Length: ${text.length}');
print('Uppercase: ${text.toUpperCase()}');
print('Lowercase: ${text.toLowerCase()}');
// String methods
print('Contains "Dart": ${text.contains('Dart')}');
print('Starts with "Hello": ${text.startsWith('Hello')}');
print('Replace: ${text.replaceAll('World', 'Universe')}');
// String interpolation
String name = 'Alice';
int age = 30;
print('Name: $name, Age: $age');
}Output:
Length: 17
Uppercase: HELLO DART WORLD
Lowercase: hello dart world
Contains "Dart": true
Starts with "Hello": true
Replace: Hello Dart Universe
Name: Alice, Age: 30
🔹 List Operations
Working with lists (arrays):
void main() {
List numbers = [1, 2, 3, 4, 5];
// Basic operations
print('List: $numbers');
print('Length: ${numbers.length}');
print('First: ${numbers.first}');
print('Last: ${numbers.last}');
// Adding elements
numbers.add(6);
numbers.addAll([7, 8]);
print('After adding: $numbers');
// List methods
print('Contains 3: ${numbers.contains(3)}');
print('Index of 4: ${numbers.indexOf(4)}');
// Filtering and mapping
var evenNumbers = numbers.where((n) => n % 2 == 0).toList();
print('Even numbers: $evenNumbers');
} Output:
List: [1, 2, 3, 4, 5]
Length: 5
First: 1
Last: 5
After adding: [1, 2, 3, 4, 5, 6, 7, 8]
Contains 3: true
Index of 4: 3
Even numbers: [2, 4, 6, 8]
🔹 Map Operations
Working with key-value pairs:
void main() {
Map ages = {
'Alice': 25,
'Bob': 30,
'Charlie': 35
};
// Basic operations
print('Ages: $ages');
print('Alice age: ${ages['Alice']}');
print('Keys: ${ages.keys.toList()}');
print('Values: ${ages.values.toList()}');
// Adding and updating
ages['David'] = 28;
ages['Alice'] = 26; // Update existing
print('Updated: $ages');
// Map methods
print('Contains Alice: ${ages.containsKey('Alice')}');
print('Contains age 30: ${ages.containsValue(30)}');
// Iterating
ages.forEach((name, age) {
print('$name is $age years old');
});
} Output:
Ages: {Alice: 25, Bob: 30, Charlie: 35}
Alice age: 25
Keys: [Alice, Bob, Charlie]
Values: [25, 30, 35]
Updated: {Alice: 26, Bob: 30, Charlie: 35, David: 28}
Contains Alice: true
Contains age 30: true
Alice is 26 years old
Bob is 30 years old
Charlie is 35 years old
David is 28 years old
🔹 DateTime and Duration
Working with dates and time:
void main() {
// Current date and time
DateTime now = DateTime.now();
print('Current time: $now');
// Creating specific dates
DateTime birthday = DateTime(1990, 5, 15);
print('Birthday: $birthday');
// Date operations
DateTime tomorrow = now.add(Duration(days: 1));
DateTime lastWeek = now.subtract(Duration(days: 7));
print('Tomorrow: $tomorrow');
print('Last week: $lastWeek');
// Duration calculations
Duration age = now.difference(birthday);
print('Age in days: ${age.inDays}');
print('Age in years: ${(age.inDays / 365).floor()}');
}