List Specific Operations

Retrieving elements by index

                  val numbers = listOf(1, 2, 3, 4)
println(numbers.get(0))
println(numbers[0])
//numbers.get(5)                         // exception!
println(numbers.getOrNull(5))             // null
println(numbers.getOrElse(5, {it}))        // 5
                

                    let numbers = [1, 2, 3, 4]
print(numbers.get(0))
print(numbers[0])
//numbers.get(5)                         // exception!
print(numbers.getOrNull(5))             // null
print(numbers.getOrElse(5, {it}))        // 5
                  

Retrieving list parts

                  val numbers = (0..13).toList()
println(numbers.subList(3, 6))
                

                    let numbers = (0..13).toList()
print(numbers.subList(3, 6))
                  

Linear search

                  val numbers = listOf(1, 2, 3, 4, 2, 5)
println(numbers.indexOf(2))
println(numbers.lastIndexOf(2))
                

                    let numbers = listOf(1, 2, 3, 4, 2, 5)
print(numbers.indexOf(2))
print(numbers.lastIndexOf(2))
                  

                  val numbers = mutableListOf(1, 2, 3, 4)
println(numbers.indexOfFirst { it > 2})
println(numbers.indexOfLast { it % 2 == 1})
                

                    let numbers = mutable[1, 2, 3, 4]
print(numbers.indexOfFirst { $0 > 2})
print(numbers.indexOfLast { $0 % 2 == 1})
                  

Binary search in sorted lists

                  val numbers = mutableListOf("one", "two", "three", "four")
numbers.sort()
println(numbers)
println(numbers.binarySearch("two"))  // 3
println(numbers.binarySearch("z")) // -5
println(numbers.binarySearch("two", 0, 2))  // -3
                

                    let numbers = mutableListOf("one", "two", "three", "four")
numbers.sort()
print(numbers)
print(numbers.binarySearch("two"))  // 3
print(numbers.binarySearch("z")) // -5
print(numbers.binarySearch("two", 0, 2))  // -3
                  

Comparator binary search

                  val productList = listOf(
    Product("WebStorm", 49.0),
    Product("AppCode", 99.0),
    Product("DotTrace", 129.0),
    Product("ReSharper", 149.0))
​
println(productList.binarySearch(Product("AppCode", 99.0), compareBy<Product> { it.price }.thenBy { it.name }))
                

                    let productList = listOf(
    Product("WebStorm", 49.0),
    Product("AppCode", 99.0),
    Product("DotTrace", 129.0),
    Product("ReSharper", 149.0))
​
print(productList.binarySearch(Product("AppCode", 99.0), compareBy<Product> { it.price }.thenBy { it.name }))
                  

                  val colors = listOf("Blue", "green", "ORANGE", "Red", "yellow")
println(colors.binarySearch("RED", String.CASE_INSENSITIVE_ORDER)) // 3
                

                    let colors = listOf("Blue", "green", "ORANGE", "Red", "yellow")
print(colors.binarySearch("RED", String.CASE_INSENSITIVE_ORDER)) // 3
                  

Comparison binary search

                  data class Product(val name: String, val price: Double)
​
fun priceComparison(product: Product, price: Double) = sign(product.price - price).toInt()
​
fun main() {
    val productList = listOf(
        Product("WebStorm", 49.0),
        Product("AppCode", 99.0),
        Product("DotTrace", 129.0),
        Product("ReSharper", 149.0))
​
    println(productList.binarySearch { priceComparison(it, 99.0) })
}
                

                    data class Product(let name: String, let price: Double)
​
func priceComparison(product: Product, price: Double) = sign(product.price - price).toInt()
​
func main() {
    let productList = listOf(
        Product("WebStorm", 49.0),
        Product("AppCode", 99.0),
        Product("DotTrace", 129.0),
        Product("ReSharper", 149.0))
​
    print(productList.binarySearch { priceComparison(it, 99.0) })
}
                  

Adding

                  val numbers = mutableListOf("one", "five", "six")
numbers.add(1, "two")
numbers.addAll(2, listOf("three", "four"))
println(numbers)
                

                    let numbers = mutableListOf("one", "five", "six")
numbers.add(1, "two")
numbers.addAll(2, listOf("three", "four"))
print(numbers)
                  

Updating

                  val numbers = mutableListOf("one", "five", "three")
numbers[1] =  "two"
println(numbers)
                

                    let numbers = mutableListOf("one", "five", "three")
numbers[1] =  "two"
print(numbers)
                  

                  val numbers = mutableListOf(1, 2, 3, 4)
numbers.fill(3)
println(numbers)
                

                    let numbers = mutable[1, 2, 3, 4]
numbers.fill(3)
print(numbers)
                  

Removing

                  val numbers = mutableListOf(1, 2, 3, 4, 3)    
numbers.removeAt(1)
println(numbers)
                

                    let numbers = mutableListOf(1, 2, 3, 4, 3)    
numbers.removeAt(1)
print(numbers)
                  

                  val numbers = mutableListOf(1, 2, 3, 4, 3)    
numbers.removeFirst()
numbers.removeLast()
println(numbers)
​
val empty = mutableListOf<Int>()
// empty.removeFirst() // NoSuchElementException: List is empty.
empty.removeFirstOrNull() //null
                

                    let numbers = mutableListOf(1, 2, 3, 4, 3)    
numbers.removeFirst()
numbers.removeLast()
print(numbers)
​
let empty = mutableListOf<Int>()
// empty.removeFirst() // NoSuchElementException: List is empty.
empty.removeFirstOrNull() //null
                  

Sorting

                  val numbers = mutableListOf("one", "two", "three", "four")
​
numbers.sort()
println("Sort into ascending: $numbers")
numbers.sortDescending()
println("Sort into descending: $numbers")
​
numbers.sortBy { it.length }
println("Sort into ascending by length: $numbers")
numbers.sortByDescending { it.last() }
println("Sort into descending by the last letter: $numbers")
​
numbers.sortWith(compareBy<String> { it.length }.thenBy { it })
println("Sort by Comparator: $numbers")
​
numbers.shuffle()
println("Shuffle: $numbers")
​
numbers.reverse()
println("Reverse: $numbers")
                

                    let numbers = mutableListOf("one", "two", "three", "four")
​
numbers.sort()
print("Sort into ascending: $numbers")
numbers.sortDescending()
print("Sort into descending: $numbers")
​
numbers.sortBy { it.length }
print("Sort into ascending by length: $numbers")
numbers.sortByDescending { it.last() }
print("Sort into descending by the last letter: $numbers")
​
numbers.sortWith(compareBy<String> { it.length }.thenBy { $0 })
print("Sort by Comparator: $numbers")
​
numbers.shuffle()
print("Shuffle: $numbers")
​
numbers.reverse()
print("Reverse: $numbers")