Kotlin save indexes of a specific char repeating in a string

Question

String example (not necessary A and B, but not X): AAAXBBXBXBBB I want to find all occoruncaes of X and save them in an array.

I wrote a function:

val arrayList = ArrayList<Int>()
fun findAllX(str: String){
    for(i in 0 until str.length){
        if(str[i] == 'X'){
            arrayList.add(i)
        }
    }
}

Result in this example: arrayList that contains integers 3, 6, 8

Is there a better/cleaner way to write this?

`AAAXBBXBXBBB` this is the string, right? And now you want to get `X` from this string? — Ali, Sep 17 '20 at 12:47
https://stackoverflow.com/questions/5034442/indexes-of-all-occurrences-of-character-in-a-string — John Boker, Sep 17 '20 at 13:35

score 1 · Accepted Answer · answered Sep 17 '20 at 14:25

1

Here is a one-liner:

"AAAXBBXBXBBB".withIndex().filter { it.value == 'X' }.map { it.index }.toTypedArray()

answered Sep 17 '20 at 14:25

Михаил Нафталь

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Kotlin save indexes of a specific char repeating in a string

1 Answers1