Dart Fundamentals: Basic Syntax and Data Types for Flutter

Welcome to the foundational elements of Dart, the programming language that powers Flutter. Understanding Dart's basic syntax and data types is crucial for building robust and efficient Flutter applications. This module will guide you through the essential building blocks of Dart.

Your First Dart Program

Every Dart program begins with a

code

main()

function. This is the entry point where your program execution starts. The

code

print()

function is used to display output to the console.

What is the entry point for any Dart program?

The main() function.

Here's a simple example:

dart

void main() {
  print('Hello, Dart!');
}

Variables and Data Types

Variables are containers for storing data values. Dart is a statically typed language, meaning you declare the type of a variable. However, Dart also supports type inference, where the compiler can often deduce the type.

Dart uses static typing and type inference for variables.

Variables hold data. You can explicitly declare their type (like int for integers) or let Dart figure it out.

In Dart, you declare variables using keywords like var, final, and const. var allows the variable's type to be inferred and can be reassigned. final means the variable can only be assigned once, and const means it's a compile-time constant. Explicitly typing variables, such as int count = 10; or String name = 'Alice';, is also common and recommended for clarity.

Common Data Types

Type	Description	Example
int	Whole numbers (e.g., -1, 0, 100)	<code>int age = 30;</code>
double	Floating-point numbers (e.g., 3.14, -0.5)	<code>double price = 19.99;</code>
String	Sequences of characters (text)	<code>String message = 'Welcome';</code>
bool	Boolean values (true or false)	<code>bool isActive = true;</code>
List	Ordered collection of elements (like arrays)	<code>List<int> numbers = [1, 2, 3];</code>
Map	Unordered collection of key-value pairs	<code>Map<String, int> scores = {'Alice': 95, 'Bob': 88};</code>

Operators

Operators are symbols that perform operations on variables and values. Dart supports arithmetic, relational, logical, and assignment operators.

Operators perform actions on data.

Operators like +, -, *, /, ==, !=, &&, || are used to manipulate and compare data.

Arithmetic operators include + (addition), - (subtraction), * (multiplication), / (division), and % (modulo). Relational operators like == (equal to), != (not equal to), > (greater than), < (less than), >= (greater than or equal to), and <= (less than or equal to) are used for comparisons. Logical operators && (AND), || (OR), and ! (NOT) combine boolean expressions. Assignment operators like = and += are used to assign values.

What operator is used to check if two values are equal?

The == operator.

Control Flow Statements

Control flow statements allow you to execute different blocks of code based on certain conditions or to repeat code execution.

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Common control flow statements include

code

if-else

for conditional execution,

code

for

loops for iteration,

code

while

loops, and

code

switch

statements for multi-way branching.

Understanding these fundamental syntax elements and data types is the bedrock of your journey into Flutter development. Practice writing small Dart programs to solidify your grasp!

Learning Resources

Dart Language Tour(documentation)

The official and comprehensive guide to Dart's syntax, data types, and core features.

Flutter Docs: Dart Fundamentals(documentation)

While this link is about state management, Flutter's official documentation often links to or embeds Dart fundamentals relevant to app development.

Learn Dart in 10 Minutes(video)

A quick and engaging video tutorial that covers the essential Dart syntax and concepts.

Dart Basics: Variables, Data Types, Operators(video)

A detailed video walkthrough of Dart's basic syntax, including variables, data types, and operators.

Dart for Beginners: Syntax and Data Types(blog)

A beginner-friendly blog post explaining Dart's core syntax and common data types with clear examples.

Dart Data Types Explained(blog)

GeeksforGeeks provides a clear explanation of Dart's built-in data types and their usage.

Dart Operators(documentation)

Official documentation detailing all the operators available in Dart and how they function.

Understanding Dart's `var`, `final`, and `const`(blog)

A helpful article clarifying the differences and use cases for Dart's variable declaration keywords.

Dart Control Flow Statements(tutorial)

A tutorial covering Dart's conditional statements (`if-else`, `switch`) and loops (`for`, `while`).

Dart (programming language) - Wikipedia(wikipedia)

Provides a general overview of the Dart language, its history, and key features.