How to add multiple chars in .endsWith() Kotlin

user_13344149 0
Viewed 421

I have an expression when in my code, which does:

when{
    currentOpperand.text.toString().endsWith("+") || 
    currentOpperand.text.toString().endsWith("-") || 
    currentOpperand.text.toString().endsWith("÷") ||
    currentOpperand.text.toString().endsWith("×") ||
    currentOpperand.text.toString().endsWith(".") ||
    currentOpperand.text.toString().endsWith("")
    ->{
        currentOpperand.text = currentOpperand.text.toString() + ""
    }

I want to make this code shorter, like:

when{
    currentOpperand.text.toString().endsWith("+", "-", "÷", "×", ".", "") ->{
        currentOpperand.text = currentOpperand.text.toString() + ""
    }

But android studio gives me an error:

None of the following functions can be called with the argument supplied

If it's possible, comment please another way to do these using things like: lastIndexOfAny or etc. (I want to do this action in any way possible with the shortest result in code)

kotlin android
3 Answers

You can use the extension function. Here is how it looks:

fun String.endsWithMulti(vararg chars: Char): Boolean
{
    chars.forEach {
        if (endsWith(it))
        {
            return true
        }
    }
    return false
}

fun main()
{
    // Test
    println("TEST_+".endsWithMulti('+', '-', '/', '*')) // true
    println("TEST_-".endsWithMulti('+', '-', '/', '*')) // true
    println("TEST_O".endsWithMulti('+', '-', '/', '*')) // false
}

So your when statement will look something like this:

when
{
    stringYouWantToCheck.endsWithMulti('+', '-', '÷', '×', '.') ->
    {
        // do something
    }
    else ->
    {
        // string doesn't end with '+', '-', '÷', '×', '.'
    }
}

As @IR42 mentioned in the comment You can simplify endsWithMulti

fun String.endsWithMulti(vararg chars: Char): Boolean
{
    return chars.any {
        endsWith(it)
    }
}
user_133632050

You can do like this:

var doesExist = currentOpperand.text.last().toString() in arrayOf("+", "-", "÷", "×", ".", "")

when{
    doesExist ->{
    currentOpperand.text = currentOpperand.text.toString() + ""
    }
}

But the question is: currentOpperand.text = currentOpperand.text.toString() + "" is redundant, of no use. Why you're doing so?

user_58823070

You could use regex:

   val regex = """\+|\.|\-|×|÷| $""".toRegex()  
   val matched = regex.containsMatchIn(currentOpperand.text.toString()) 
   if(matched)
       currentOpperand.text = currentOpperand.text.toString() + "" //this line is Questionable，maybe you should do other things.
user_17530730
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