List

About List

A List in the Dart programming language is an inherent data type that represents an ordered collection of elements. Each element within a List should typically have the same data type, whether it's integers, floating-point numbers, strings, or other objects.

Lists can be useful for:

Storing data about a list of things, such as a shopping list, a to-do list, or a contact list;
Storing data about a sequence of events, such as a history list or a list of steps that need to be taken to complete a task.

Syntax

Let's look at the scheme of creating a List:

List - command to create a list;
<elements_type>- the data type for values will be stored in the middle of the list;
list_name - list name;
[ element_1, element_2] - Commas (,) separate the list elements.

Example 1

Example of creating a List with int values:

main


              1
            
List<int> numbers = [1, 2, 3, 4, 5];

List of integer numbers;
<int> type elements from List.

Example 2

Frequently, we initialize an empty List with the intention of populating it with data that we will acquire at a later point, such as input from a user.

main


              1
            
 List<bool> data = [];

An empty List for bool values was created above.

Adding Items

Let's add a value to the already existing list of numbers.

main


              123456
            
void main() {
  List<int> numbers = [111, 22, 32];
  print(numbers); // output [111, 22, 32]
  numbers.add(6); // Adding an item to a list
  print(numbers); // output [111, 22, 32, 6]
}

Let's break down the new command in detail:

numbers - list name;
add() - command that adds elements to a list;
6 - the value we want to add to the list.

Deleting Items

The remove() function removes the first occurrence of the specified item in the list.

main


              123456
            
void main() {
  List<int> numbers = [11, 22, 23];
  print(numbers); // [11, 22, 23]
  numbers.remove(22);
  print(numbers); // [11, 23]
}