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List access

Learn to access list elements by index.

List access

You reach List elements by index. Indexing is zero-based: the first element is list[0], the second list[1], and so on. The index is written inside square brackets.

For example in var numbers = [10, 20, 30]; the value of numbers[0] is 10, numbers[1] is 20, numbers[2] is 30. The index must be less than the list length; otherwise an error is thrown.

Index bounds

When accessing a list the index must be less than the length. The list [10, 20, 30] has 3 elements; valid indices are 0, 1, 2. Writing numbers[3] or numbers[5] throws a runtime error (RangeError).

Negative indices are not supported. You can reach the last element with numbers[numbers.length - 1] or with Dart's numbers.last property. Practical tip: in a loop use indices from 0 to length - 1.

Practice Print the second element

Declare a List with var numbers = [10, 20, 30];. Print the second element with print(numbers[1]);. The output on a single line must be 20.

Starter code

main.dart
// Declare numbers, print the second element

Sample solution

main.dart
var numbers = [10, 20, 30];
print(numbers[1]);

Expected output

20

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 Get the first element

Question 
var numbers = [10, 20, 30];
print(numbers____);
Answer 
var numbers = [10, 20, 30];
print(numbers[0]);

Explanation: numbers[0] gives the first element.

2 What does numbers[1] give?

main.dart
var numbers = [10, 20, 30];
print(numbers[1]);
  • 20 Correct answer
  • 30
  • 10
  • 1

Explanation: Indexing is zero-based; numbers[1] is the second element, 20.

3 Match each part to its job

Term Meaning
[0] First element
[1] Second element
length - 1 Last index
[i] I-th element

All lessons in Beginner

1 Dart basics

  1. What is Dart?
  2. Your first program
  3. dart run
  4. Comments
  5. String interpolation
  6. Summary - Dart basics

2 Variables

  1. var and type
  2. final
  3. const
  4. late
  5. Null safety
  6. Summary - Variables

3 Data types

  1. Integer types
  2. Floating-point types
  3. bool and String
  4. Type inference
  5. dynamic
  6. Summary - Data types

4 Project: Calculator

  1. Project design
  2. Add and subtract
  3. Multiply and divide
  4. Error handling
  5. Putting it together

5 Operators

  1. Arithmetic operators
  2. Assignment operators
  3. Comparison operators
  4. Logical operators
  5. Null-aware operators
  6. Summary - Operators

6 Strings

  1. Creating strings
  2. String interpolation
  3. length and methods
  4. substring
  5. contains and indexOf
  6. Summary - Strings

7 Conditionals

  1. The if statement
  2. else and else if
  3. switch
  4. Pattern matching
  5. Ternary
  6. Summary - Conditionals

8 Loops

  1. The for loop
  2. The while loop
  3. The do-while loop
  4. for-in
  5. break and continue
  6. Summary - Loops

9 Project: Shopping cart

  1. Cart design
  2. Adding items
  3. Calculating totals
  4. Listing the cart
  5. Putting it together

10 Lists

  1. Creating lists
  2. List access
  3. add and remove
  4. length and contains
  5. List methods
  6. Summary - Lists

11 Sets and Maps

  1. Set
  2. Set operations
  3. Map
  4. Map operations
  5. Map iteration
  6. Summary - Sets and Maps

12 Functions

  1. Defining functions
  2. Return values
  3. Arrow functions
  4. Optional parameters
  5. First-class functions
  6. Summary - Functions

13 Null safety in depth

  1. Nullable types
  2. Null-aware operators
  3. The ! operator
  4. late
  5. Null check
  6. Summary - Null safety

14 Class basics

  1. class
  2. Constructor
  3. Instance variables
  4. Methods
  5. this
  6. Summary - Class basics

15 Project: To-do CLI

  1. Task model
  2. Adding tasks
  3. Listing tasks
  4. Completing tasks
  5. Putting it together

16 Advanced string operations

  1. split and join
  2. replace
  3. trim and pad
  4. RegExp
  5. StringBuffer
  6. Summary - Advanced strings

17 Enums

  1. Defining enums
  2. Enum values
  3. Enhanced enums
  4. switch with enum
  5. Enum and patterns
  6. Summary - Enums

18 Exceptions

  1. try/catch
  2. throw
  3. finally
  4. The Exception class
  5. on clause
  6. Summary - Exceptions

19 Async basics

  1. Future
  2. async/await
  3. then
  4. Future.error
  5. Future.wait
  6. Summary - Async basics

20 Beginner final

  1. Project design
  2. Classes
  3. Collections
  4. Error handling
  5. Putting it together