CODEWITHSUNDEEP
javaandroidkotlinequals
Suryakant Bharti
Suryakant Bharti

Reputation: 701

In Kotlin, how to refactor "if else" and use "when" instead of it with equals ignore case comparison?

I want to refactor this code for using "when" instead of "if else". How can I use Kotlin's when(char) with ignore case for my situation?

    if(char.equals("A", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade1))
    else if(char.equals("B", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade2))
    else if(char.equals("C", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade3))
    else if(char.equals("D", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade4))
    else if(char.equals("E", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade5))
    else if(char.equals("F", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade6))
    ...
    else if(char.equals("Z", true))
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade26))
    else
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade27))

Please let me know if there is a way to do this in a good way.

Upvotes: 1

Views: 537

Answers (3)

SMSQO
SMSQO

Reputation: 197

Maybe this is what you want:

val ch = 'A'
val src = when (ch.toUpperCase()) {
    'A' -> R.color.colorBgShade1
    'B' -> R.color.colorBgShade2
    // ...
    'Z' -> R.color.colorBgShade26
    else -> R.color.colorBgShade27
}
background.setTint(ContextCompat.getColor(context, src))

But using Map is always a better way for such problem.

Upvotes: 2

Arpit Shukla
Arpit Shukla

Reputation: 10493

A simpler way to implement what you need is:

val colorMap = mapOf (
    'A' to R.color.colorBgShade1,
    'B' to R.color.colorBgShade2,
    ...
    ...
)

val char = 'G'
val bgColor = colorMap[char] ?: R.color.colorBgShade27
background.setTint(ContextCompat.getColor(context, bgColor)

Upvotes: 4

Nhân Khuất Văn
Nhân Khuất Văn

Reputation: 270

This is what you need.

val char = "G"
when {
    char.equals("A", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade1))
    }
    char.equals("B", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade2))
    }
    char.equals("C", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade3))
    }
    char.equals("D", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade4))
    }
    char.equals("E", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade5))
    }
    char.equals("F", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade6))
    }
    char.equals("Z", true) -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade26))
    }
    else -> {
        background.setTint(ContextCompat.getColor(context, R.color.colorBgShade27))
    }
}

But the best way is that you should do it like this.

data class Alpha(val alpha:String , val color: Int)

fun generateData() {
    val listAlpha = arrayListOf<Alpha>()
    listAlpha.add(Alpha("A", R.color.colorBgShade1))
    listAlpha.add(Alpha("B", R.color.colorBgShade2))
    listAlpha.add(Alpha("C", R.color.colorBgShade3))
    listAlpha.add(Alpha("D", R.color.colorBgShade4))

    var char = "D"
    val alphaFindResult = listAlpha.single { it.alpha.equals(char, true) }
    background.setTint(ContextCompat.getColor(context, alphaFindResult.color))
}

Upvotes: 2

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