Dart notes by chat gpt
Certainly! Let's start by covering the fundamentals of the Dart programming language and then delve into object-oriented programming (OOP) concepts in Dart.
### Dart Fundamentals:
#### 1. Variables and Data Types:
In Dart, you can declare variables using the `var`, `final`, or `const` keywords. Dart has various data types, including:
- `int` for integers.
- `double` for floating-point numbers.
- `String` for text.
- `bool` for boolean values.
- `List` and `Map` for collections.
Here's an example of variable declaration:
```dart
var age = 25;
String name = "John";
final piValue = 3.14159;
```
#### 2. Functions:
Functions are blocks of code that can be reused. You can define a function in Dart like this:
```dart
int add(int a, int b) {
return a + b;
}
```
#### 3. Control Flow:
Dart supports common control flow structures, including `if`, `else`, `switch`, `for`, `while`, and `do-while` loops.
```dart
if (condition) {
// Code to execute if the condition is true.
} else {
// Code to execute if the condition is false.
}
for (var i = 0; i < 5; i++) {
// Code to repeat five times.
}
```
#### 4. Lists and Maps:
Dart provides collections like lists and maps to work with groups of data.
```dart
List<int> numbers = [1, 2, 3, 4, 5];
Map<String, int> ages = {'Alice': 30, 'Bob': 25};
```
#### 5. Classes and Objects (OOP):
Now, let's dive into object-oriented programming concepts in Dart.
### Object-Oriented Programming (OOP) in Dart:
#### 1. Classes and Objects:
In OOP, a class is a blueprint for creating objects. An object is an instance of a class.
```dart
class Person {
String name;
int age;
Person(this.name, this.age);
void sayHello() {
print('Hello, my name is $name and I am $age years old.');
}
}
void main() {
var person = Person('Alice', 30);
person.sayHello();
}
```
#### 2. Inheritance:
Dart supports inheritance, allowing you to create new classes based on existing ones.
```dart
class Student extends Person {
String major;
Student(String name, int age, this.major) : super(name, age);
void study() {
print('$name is studying $major.');
}
}
```
#### 3. Encapsulation:
Dart allows you to control access to class members using `public`, `private`, and `protected` keywords. By default, members are public.
```dart
class Circle {
double _radius; // Private member
Circle(this._radius);
double calculateArea() {
return 3.14159 * _radius * _radius;
}
}
```
#### 4. Polymorphism:
Polymorphism allows objects of different classes to be treated as objects of a common superclass.
```dart
void printInfo(Person person) {
print('Name: ${person.name}, Age: ${person.age}');
}
void main() {
var alice = Person('Alice', 30);
var bob = Student('Bob', 25, 'Computer Science');
printInfo(alice); // Calls printInfo with a Person object.
printInfo(bob); // Calls printInfo with a Student object.
}
```
These are the fundamental concepts of Dart and object-oriented programming in Dart. Practice and experimentation are essential to solidify your understanding, so try writing some Dart code to apply these concepts in practice.
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