TheDeveloperBlog.com
C-Sharp | Java | Python | Swift | GO | WPF | Ruby | Scala | F# | JavaScript | SQL | PHP | Angular | HTML
Scala Array Examples: Apply and Update
Use an Array and accesses elements with apply. Invoke update and clone.Array. An array has elements. It has strings like "tree" and "bird." And these can be updated. We can change the "bird" into a "flower."
With mutable elements, arrays provide an important ability to our linear collections in Scala. A list is immutable, but with arrays we can change elements.
An example. Here we create a 4-element Int array. With val we make the "numbers" variable so it cannot be reassigned. But the array elements are still mutable.
Apply: This method gets the value of an element from the array. We pass the index of the element. In an array this starts at 0.
Scala program that uses Array, apply
// An array of four Ints.
val numbers = Array(10, 20, 30, 40)
// Get first number in array with apply.
val first = numbers.apply(0)
println(first)
// Get last number.
val last = numbers.apply(numbers.length - 1)
println(last)
Output
10
40
Update. This modifies an element in an array. The first argument is the index of the element. And the second argument is the new value of the element.
Scala program that uses update
// An array of three strings.
val plants = Array("tree", "moss", "fern")
// Update first element to be a new string.
plants.update(0, "flower")
// Display array.
plants.foreach(println(_))
Output
flower
moss
fern
Short syntax. We can apply and update elements in an array with an index. This is a short hand syntax for apply and update. Here we get and change the first element.
Scala program that uses short array syntax
val codes = Array(5, 10, 15)
// Get first element.
val first = codes(0)
println(first)
// Update first element.
codes(0) = 50
// Get first element again.
println(codes(0))
Output
5
50
Convert to Array. Often in Scala we use lists. With lists we have an immutable collection. With arrays, meanwhile, we can change elements.Convert
Two dimensions. With Array.ofDim we create two-dimensional (up to five-dimensional) arrays in Scala. A type argument (to indicate element type) is needed.2D List, 2D Array
Unlike lists, arrays are mutable. We can use update to change their elements. Arrays can be used in a similar way to lists. They store elements of a single type in a linear order.
© TheDeveloperBlog.com
The Dev Codes
Related Links:
- Scala Convert: String to Int, List and Array
- Scala Odd and Even Numbers
- Scala Regex, R Examples: findFirstMatchIn
- Scala Interview Questions (2021)
- Scala Class Examples: Trait Keyword
- Scala indexOf: Lists and Strings
- Scala Int Examples: Max and Min
- Scala 2D List, Array Examples: Array.ofDim
- Scala Def: return Unit and Lambdas
- Scala Initialize List: List.newBuilder, List.empty
- Scala Option: None, get and getOrElse
- Scala Exception Handling: Try, Catch and Throw
- Scala Map Examples
- Scala String Examples: StringLike
- Scala Match and Case Examples
- Scala Remove Duplicates From List: Distinct Example
- Scala If, Else Example (Match Case If)
- Scala Console: println, printf and readLine
- Scala Strip Strings: stripLineEnd and stripMargin
- Scala Vector Examples
- Scala Var and Val (Variables and Constants)
- Learn Scala Tutorial
- Scala Keywords
- Scala format and formatted Strings
- Scala List Examples
- Scala StringBuilder Examples
- Scala Set Examples: contains, intersect
- Scala Tuple Examples (Return Multiple Values)
- Scala For to, until, while Loop Examples
- Scala Slice: Substring, List Slice
- Scala Sorted List Examples: Ordering.Int
- Scala Split String Examples
- Scala Array Examples: Apply and Update
- Scala Range Examples: Start, End and Step