Filtering an array based on an array of Int-CodePudding

I have a Drink object that has a property called strength. Strength is an Integer with values of 0,1,2 or 3.

Now in my project, I display all of the Drink objects in a List View. At the top of the list view, there's a filtering section for the user to filter the Drink objects based on strength. These are CHECK BOXES, meaning users can select as little as 1 filter, or as much as 4. This gets saved to SharedPreferences as an Int Array.

data class Drink(val theDrinkName:String, val strength:Int)


object DrinkData {

    const val low = 0
    const val medium = 1
    const val strong = 2
    const val intense = 3

    fun generateAllDrinks():Array<Drink> {
        return arrayOf(
            Drink("Vodka", medium),
            Drink("Shirley Temple", low),
            Drink("rum", strong),
            Drink("Gin", medium),
            Drink("151", intense),
            Drink("99", strong)
        )
    }

}

Here's how I am generating all of the data:

val allDrinks = DrinkData.generateAllDrinks().sortedWith(
    compareBy<Drink> { it.theDrinkName.first().isDigit() }
        .thenBy { it.theDrinkName.toLowerCase() }
)

I need to be able to filter the strength property of this data based on an Int Array. (An Int Array is what gets saved to SharedPreferences.)

val filteredStrengthArray = arrayListOf<Int>(2,3)

This would filter allDrinks to rum, 151, 99.

My progress:

This is the closet I got to achieving this filtering.

    val allDrinks = DrinkData.generateAllDrinks().sortedWith(
        compareBy<Drink> { it.theDrinkName.first().isDigit() }
            .thenBy { it.theDrinkName.toLowerCase() }
    ).filter { it.strength == 2 || it.strength == 3 }

The problem is I need to filter by an Int Array to align what is saved in SharedPreferences.

How can I filter the strength property of this data by providing an Int Array?

CodePudding user response：

The first solution that comes to mind is checking if strength property is contained by filteredStrengthArray:

val filteredStrengthArray = arrayListOf<Int>(2,3)
val allDrinks = DrinkData.generateAllDrinks().sortedWith(
        ...
    ).filter { filteredStrengthArray.isEmpty() || filteredStrengthArray.contains(it.strength) }