Hi, there is a problem with my code but I can't figure out what it is. Basically, when I select distinct characters, the fourth one onwards gets double its value. But say I select four Es (or four of any same character), the fourth E is not multiplied by 2.

fun getWordValue() {
        val workingArray = repository.arr.distinct()
        val list = mutableListOf(0)

        word.value!!.forEach { c ->
            workingArray.forEach {
                if (it.name.contains(c)) {
                    when (c) {
                        word.value!![0] -> list.add(it.value)
                        word.value!![1] -> list.add(it.value)
                        word.value!![2] -> list.add(it.value)
                        else -> list.add((it.value * 2))
                    }
                }
            }
        }
        wordValue.value = list.sum()
        saveWordValue(wordValue.value!!)
    }

I'd be grateful for some help, thanks!

This is a bit hard to understand because the code mentions a few things that are defined elsewhere. Can you simplify the example at all? Either that, or give some more info about what

repository

,

word

and

wordValue

are.

What do you mean by select? It'd be nice to extract just the problematic piece of code for reproducibility. Here this function is entangled with many other global things that you read or write to (which by the way is a smell, given the name of the function).

Just barely 😄

Thanks, let me think 🙂

The first suggestion that comes to mind is to change

word.value!!.forEach { c ->

to

word.value!!.forEachIndexed { i, c ->

Where

i

will give you the position of the character in the word.

Given a character and its index in the word, can you find its value?

Given a character and its index in the word, can you find its value?

Actually this would be easy if instead of converting the letters array by just using

distinct()

you used a

Map<Char, Int>

from letter to value:

val lettersToValues = repository.arr.associate { it.name to it.value }

Sorry for the late reply; I went for a walk... Thank you, I'll try out your suggestions! 😊

I don't know if anyone answered the question of what the problem is with the existing code. The problem is that your

when

statement will always hit the first condition in the scenario you described because it's comparing the values. So if your word is "EXCEPT", the first "E" and the fourth "E" will match

word.value!![0]

because that evaluates to "E".

Thanks for this! I managed to make it work in the end by getting rid of the

when

statement in order to make my code less awkward, and using the suggestions that were made above. But it's good to know why this did not work in the first place. 😊 Here is what the code looks like now:

fun getWordValue() {
        val list = mutableListOf(0)
        val lettersToValues = repository.arr.associate { it.name to it.value }

        word.value!!.forEachIndexed() { i, c: Char ->
            if (i in 0..2) {
                list.add(lettersToValues.getValue(c.toString()))
            } else {
                list.add(lettersToValues.getValue(c.toString()) * 2)
            }
        }
        wordValue.value = list.sum()
        saveWordValue(wordValue.value!!)
    }

Also, why do you add to a list if all you want is a sum? You could just increment a total instead

this seems like a great use case for fold, if you want to avoid the mutable list altogether

Coming back to this, is there any plausible reason why from the tenth char onwards values stop being multiplied by 2?

fun getWordValue() {
        val lettersToValues = repository.arr.associate { it.name to it.value }
        word.value!!.forEachIndexed { i, c: Char ->
                if (i in 0..2) {
                    lettersToValues.getValue(c.toString())
                } else {
                   lettersToValues.getValue(c.toString()) * 2
                }
                wordValue.value = c.toString().sumOf { i }
            } 
    }

I’m a little confused by your code here. You’re calling

lettersToValues.getValue(…)

but you don’t seem to do anything with the result. In an earlier version of your code you were adding it to a list, I think.

Yes, it's just that someone said it was useless to add it to a list

To answer your question, though, I can’t see anything obvious that would make the code behave differently on/after the tenth loop iteration.

but even adding it to a list causes the same issue

When I said to not add to a list, I also mentioned incrementing a counter instead. Basically instead of adding all elements to a list and then going through the list to add them all, you could use a variable that keeps the total-so-far, and increment it. But you still need to use the value anyway. You could also use

fold

which is a functional way of doing it.