F# Lists

List is a immutable collection of same type elements. It does not allow duplicate elements. It maintains order of elements.

F# Creating and initializing list Example

There are various ways to create list. Some are describing below.

F# List Example

Output:

1
2
3
4
5
6
7
8
9

F# Add new element to list Example

You can add new element into list by using :: (cons) operator. Let's see an Example.

Output:

1 2 3 4 5
0 1 2 3 4 5

F# Concatenation of Two List Example

You can concatenate two lists having same type by using @ operator. Let's see an example.

Output:

1
2
3
4
5
6
7
8
9
10

F# List properties

F# list provides important properties. It helps to optimize and maintain code too.

F# List Property Example

Ouptut:

Is list Empty: false
Length of list is 5
Head element of list is 1
Tail element of Head in the list is 2
Tail element of tail of head of list 3
Element at 1 index is 2

In F#, list provides built-in functions to sort and search elements.

F# List Sort Example

Ouptut:

0
7
10
12
23
43
54
89
90

F# List Search Example

List provides List.find () function to find element in the list. It returns the first matched element and if element not found it throws System.Collections.Generic.KeyNotFoundException Exception.

Ouptut:

10

F# Zip and Unzip functions in List

Zip function combines two lists of single values into one list of tuples. Unzip function separates one list of tuples into two lists of single values.

F# List Zip Example

Output:

Given Lists:
 List1: [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]
 List2: [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]
Result(Zipped List):
 [(1, 1); (2, 2); (3, 3); (4, 4); (5, 5); (6, 6); (7, 7); (8, 8); (9, 9);
 (10, 10)]

F# List Unzip Example

Output:

First List: [1; 3; 5]
Second List: [2; 4; 6]