Classes and objects in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a class in Flutter?

A class is a blueprint or template that defines properties and behaviors (methods) for objects. It helps organize code by grouping related data and functions.

beginner

What is an object in Flutter?

An object is an instance of a class. It holds actual values for the properties defined by the class and can use the class's methods.

beginner

How do you create an object from a class in Dart?

You create an object by calling the class name followed by parentheses, like: var myObject = MyClass();

intermediate

What is a constructor in a Dart class?

A constructor is a special method that runs when you create an object. It initializes the object's properties.

beginner

Why use classes and objects in Flutter apps?

They help organize code into reusable and manageable pieces, making apps easier to build, understand, and maintain.

What keyword is used to define a class in Dart?

A class

B object

C new

D function

The keyword 'class' is used to define a class in Dart.

How do you create an instance of a class named 'Car'?

A Car = new car();

B var car = Car();

C create Car();

D Car car = new Car[];

You create an instance by calling the class name with parentheses: var car = Car();

What does a constructor do?

A Deletes an object

B Creates a new class

C Defines a class

D Initializes an object when created

A constructor initializes an object’s properties when it is created.

Which of these is true about objects?

A Objects define methods only

B Objects are blueprints for classes

C Objects are instances of classes

D Objects cannot have properties

Objects are instances created from classes and hold data and behavior.

Why use classes in Flutter?

A To organize code into reusable parts

B To write code faster without structure

C To avoid using variables

D To make apps slower

Classes help organize code into reusable and manageable parts.

Explain in your own words what a class and an object are in Flutter.

Think about how a cookie cutter (class) makes cookies (objects).

Describe how constructors help when creating objects in Dart.

Imagine setting up a new phone with initial settings.