Kotlin 2D Array of Strings Inference Type Error Using indexOf

I am trying to use a set 2D array to pull data. I am trying to find the Index of a String object in an array, and use that Index to pull data from the same row but separate column so I don’t have a massive chain of 16 if loops for every single piece of math I need.

Here is the code snippet.

@Composable
    fun TimeCalculation(
        songVar: String, // songVar is a string that changes from another composable
        arrayOfSongs: kotlin.Array<kotlin.Array<String>>
    ) {
        if (songVar != "") {
            val index = arrayOfSongs.indexOf(songVar) // <-- Error on 'indexOf'
        } else {
            var time1 = 0.0
        }

arrayOfSongs is initialized above as follows:

val arrayOfSongs = rememberSaveable { // no errors here
    arrayOf(
        arrayOf("songTitle1", "3.46"),
        arrayOf("songTitle2", "4.22"),
// more code for a longer array follows

And I am sending the array to the Composable as follows:

TimeCalculation(
    songVar, arrayOfSongs) // no errors here

Originally, I had declared the arrayOfSongs array inside the composable, but was met with the same error.

>Solution :

The error message shown by the IDE is slightly confusing:

Type inference failed. The value of the type parameter T should be mentioned in input types (argument types, receiver type or expected type). Try to specify it explicitly.

The actual issue is that there’s a type mismatch between the elements of arrayOfSongs and the argument you’re passing to indexOf(). Each element in arrayOfSongs is an array, but you’re trying to pass a simple String.

If you’re looking for the index of the first sub-array that starts with songVar, try something like this:

val index = arrayOfSongs.indexOfFirst { it[0] == songVar }