Arrays

An array is a collection of items stored in contiguous memory locations. It's an aggregate data structure that is designed to store a group of objects of the same type. It's the most efficient data structure for storing and accessing a sequence of objects.
How to declare an array
Create an array that holds integer values:
mut ages := [18, 25, 37]
​
println(ages)
Output
[18, 25, 37]
Or create an array that holds string values:
mut users := ['vbrazo', 'donnisnoni95', 'Delta456']
​
println(users)
Output
['vbrazo', 'donnisnoni95', 'Delta456']
Note: All elements must have the same type. The following code will not compile.
mut users := ['vbrazo', 'donnisnoni95', 'Delta456', 0]
Output
~/main.v:2:43: bad array element type `int` instead of `string`
Create an empty array
If you want to create a new empty array, just declare [] followed by the data type.
mut names := []string
mut numbers := []int
Accessing element of the array
mut users := ['vbrazo', 'donnisnoni95', 'Delta456']
​
println(users[0])
println(users[2])
println(users[1])
Output
vbrazo
Delta456
donnisnoni95
Append a value to an array
<< is an operator that appends a value to the end of the array.
mut ages := [18]
ages << 47
​
println(ages)
Output
[18, 47]
It can also append an entire array.
mut ages := [18]
ages << [47, 49]
​
println(ages)
Output
[18, 47, 49]
Length/size of an array
.len method returns the length of the array.
mut names := ['Thiago', 'John']
​
println(names.len)
Output
2
In operator
in check if an element is inside an array.
mut names := ['Thiago', 'Alex', 'Joe']
​
println('Vitor' in names)
println('Thiago' in names)
Output
false
true
Slicing an array
It's easy to slice an array in V. You can slice an array with the default V slicing feature without having to call the slice () method. The syntax is like this my_array[start..end]
animals := ['lion', 'goose', 'chicken', 'turkey', 'tiger']
poultry := animals[1..4]
println(poultry) // ["goose", "chicken", "turkey"]
If you want to slice from the start of the index, just ignore it to put 0 and using instead my_array[..end] or my_array[start..].
x := ['h', 'e', 'l', 'l', 'o']
y := x[..x.len-1]
z := x[1..]
println(y) // ['h', 'e', 'l', 'l']
println(z) // ['e', 'l', 'l', '0']
Exercises
1.Write a V program to store elements in an array and print it.
2.Write a V program to read n number of values in an array and display it in reverse order.
3.Write a V program to find the sum of all elements of the array.
4.Write a V program to copy the elements of one array into another array.
5.Write a V program to count a total number of duplicate elements in an array.

Methods

Struct

Last modified 3yr ago