Your program needs to remember things.

A name. A score. A total. Without a way to hold values, your program could only print fixed text.

Variables are how Dart remembers.

Think of a labeled box

Imagine a shelf. On that shelf, you place a box. You write a label on the box. Then you put something inside.

+---------------------+
|   name: "Ali"       |
+---------------------+

That is a variable. The label is the name. The contents are the value. When your program needs the value, it looks up the box by its label and reads what is inside.

Creating a variable

In Dart, you create a variable with var:

void main() {
  var name = 'Ali';
  print(name); // Ali
}

var tells Dart you are creating a new variable. name is the label. 'Ali' is what goes inside.

When you call print(name), Dart finds the box labeled name, reads the contents, and prints them.

Multiple variables

You can have as many variables as you need:

void main() {
  var firstName = 'Ali';
  var age = 25;
 
  print(firstName); // Ali
  print(age);       // 25
}

Each variable is its own box, with its own label and its own contents.

Type inference

You did not tell Dart that firstName holds text or that age holds a number. Dart figured it out from the values you assigned.

This is called type inference.

Dart pays attention to what you put in the box. Once it knows the type, it locks it in. You will learn more about types in the next lesson.

Changing the value

You can replace what is in the box:

void main() {
  var name = 'Ali';
  print(name); // Ali
 
  name = 'Sara';
  print(name); // Sara
}

The label stays the same. The contents change.

Notice that you do not write var again when you reassign. var is only for creating the variable the first time.

Sometimes you want a value that never changes at all. Dart has two keywords for that: final and const. We cover them in Lesson 11.

Naming variables

Dart follows a naming convention called camelCase. The first word is all lowercase, and every word after it starts with a capital letter.

var firstName = 'Ali';
var lastLoginDate = '2026-01-01';
var totalScore = 100;

Not first_name. Not FirstName. Just firstName.

Dart will not reject a different style. But the Dart community follows camelCase, and so should you.

Summary