CODEWITHSUNDEEP
androidkotlin
Akash kv
Akash kv

Reputation: 429

dynamically create kotlin variable

I want to generate combinations of a string with iterable multiplication.I am try to get combination of string passed to my function.I am passing numbers and get combination of strings like 1 for abc,2 for def

fun generatexCombinations(valuePassed:String){


        val list2 = listOf("A", "B", "C")
        val list3 = listOf("D", "E", "F")
        val list4 = listOf("G", "H", "I")
        val list5 = listOf("J", "K", "L")
        val list6 = listOf("M", "N", "O")
        val list7 = listOf("P", "Q", "R", "S")
        val list8 = listOf("T", "U", "V")
        val list9 = listOf("W", "X", "Y", "Z")


        val listCombination=  mutableListOf<List<String>>()

        val charArray= valuePassed.toCharArray()
        for (char in charArray){
            when(char.toString()){
                "2"->listCombination.add(list2)
                "3"->listCombination.add(list3)
                "4"->listCombination.add(list4)
                "5"->listCombination.add(list5)
                "6"->listCombination.add(list6)
                "7"->listCombination.add(list7)
                "8"->listCombination.add(list8)
                "9"->listCombination.add(list9)
            }
        }





        //this is example of text "biryani"
        val combinationOfStrings= list2 * list4*list7*list9*list2*list6*list4

        //i want to generate above list to multiplied 
        // dynamically accroding to string value passed



    }

how can i achieve it?

i am using iterable multiplication ,please refer website below

https://www.kotlinresources.com/library/kotlindiscretemathtoolkit/

Upvotes: 0

Views: 3108

Answers (2)

Alexey Romanov
Alexey Romanov

Reputation: 170745

First, let's simplify building listCombination:

val mapOfLists = mapOf(
    '2' to listOf("A", "B", "C"),
    '3' to listOf("D", "E", "F"), 
    ...)

val charArray= valuePassed.toCharArray()
val listCombination = charArray.map { mapOfLists[it] }.filterNotNull()

Or charArray.map { mapOfLists[it]!! } if you are certain charArray won't contain characters for which you don't have a corresponding list. And then it's just

val combinationOfStrings = listCombination.reduce(List::times)

Upvotes: 1

Aloso
Aloso

Reputation: 5397

Variables can't be created dynamically. They have to be known at compile-time.

Depending on the situation, you can use arrays/lists or maps instead.

Here's a solution:

//                       0   1     2      3      4      5      6      7       8      9
private val lut = listOf("", "", "ABC", "DEF", "GHI", "JKL", "MNO", "PQRS", "TUV", "WXYZ")
        .map(String::toList)

fun generateXCombinations(numericString: String) = numericString
        .filter(Char::isDigit)
        .map { lut[it - '0'] }
        .fold(listOf("")) { acc, list ->
            val pairs = acc * list
            pairs.map { (str, char) -> str + char }
        }

EDIT: I included the library and tested it. This code creates a list of strings. Each string is one possible input on the number keyboard.

Upvotes: 1

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