Dart Programming - Lists

A very commonly used collection in programming is an array. Dart represents arrays in the form of List objects. A List is simply an ordered group of objects. The dart:core library provides the List class that enables creation and manipulation of lists.
The logical representation of a list in Dart is given below −
test_list − is the identifier that references the collection.
test_list − is the identifier that references the collection.
The list contains in it the values 12, 13, and 14. The memory blocks holding these values are known as elements.
The list contains in it the values 12, 13, and 14. The memory blocks holding these values are known as elements.
Each element in the List is identified by a unique number called the index. The index starts from zero and extends up to n-1 where n is the total number of elements in the List. The index is also referred to as the subscript.
Each element in the List is identified by a unique number called the index. The index starts from zero and extends up to n-1 where n is the total number of elements in the List. The index is also referred to as the subscript.
Lists can be classified as −
Fixed Length List
Growable List
Let us now discuss these two types of lists in detail.
A fixed length list’s length cannot change at runtime. The syntax for creating a fixed length list is as given below −
Step 1 −  Declaring a list
The syntax for declaring a fixed length list is given below −
var list_name = new List(initial_size)

The above syntax creates a list of the specified size. The list cannot grow or shrink at runtime. Any attempt to resize the list will result in an exception.
Step 2 − Initializing a list
The syntax for initializing a list is as given below −
lst_name[index] = value;

void main() { 
   var lst = new List(3); 
   lst[0] = 12; 
   lst[1] = 13; 
   lst[2] = 11; 
   print(lst); 
}
It will produce the following output −
[12, 13, 11]

A growable list’s length can change at run-time. The syntax for declaring and initializing a growable list is as given below −
Step 1 − Declaring a List
var list_name = [val1,val2,val3]   
--- creates a list containing the specified values  
OR  
var list_name = new List() 
--- creates a list of size zero 

Step 2 − Initializing a List
The index / subscript is used to reference the element that should be populated with a value. The syntax for initializing a list is as given below −
list_name[index] = value;

The following example shows how to create a list of 3 elements.
void main() { 
   var num_list = [1,2,3]; 
   print(num_list); 
}
It will produce the following output −
[1, 2, 3]

The following example creates a zero-length list using the empty List() constructor. The add() function in the List class is used to dynamically add elements to the list.
void main() { 
   var lst = new List(); 
   lst.add(12); 
   lst.add(13); 
   print(lst); 
} 
It will produce the following output −
[12, 13] 

The following table lists some commonly used properties of the List class in the dart:core library.
Returns the first element in the list.
Returns true if the collection has no elements.
Returns true if the collection has at least one element.
Returns the size of the list.
Returns the last element in the list.
Returns an iterable object containing the lists values in the reverse order.
Checks if the list has only one element and returns it.

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