uncaught typeerror in class despite setting element

So I’m making a basic brute force sudoku solver. I created a class that takes in a board string and use a constructor to set this.board = board parameter passed in

export default class SudokuSolver {
  constructor(board){
    this.board = board
  }

the first method that gets run is validBoardFormat

validBoardFormat(){
    /* possible input formats: CSV of 81 integers or string of 81 integers
    0's replace unknown numbers*/
    let cleanedBoard=[];
    let uncleanedBoard = this.board.split('') //split by character
    for (let i = 0; i<uncleanedBoard.length; i++){
      if (this.validNum(uncleanedBoard[i])){ //validate with validNum function
        cleanedBoard.push(parseInt(uncleanedBoard[i]))
      }
    }
    if (cleanedBoard.length === 81){ 
      this.board = cleanedBoard //make sure board matches correct sudoku board length
      return true
    }
    return false
  }

Let’s say for example pass in:

let boardString = "1024091501202523235" //imagine this is a valid board string
const board = new SudokuSolver(boardString)
console.log(board.validBoardFormat())

console: true

This works perfectly fine on its own.

later in the class I define a solve method

solve(){
    if (this.validBoardFormat()){
        this.validBoardFormat()
        this.configureBoardArray()
        this.solveBoard()

    } else {
      console.log('Board error')
    }
  }

The issue is when I pass this:

let boardString = "1024091501202523235" //imagine this is a valid board string
const board = new SudokuSolver(board)
console.log(board.solve())

and I run it on liveserver, I am getting this error:

Uncaught TypeError: this.board.split is not a function in the validBoardFormat function

I have been trying to troubleshoot this for a while now any help would be appreicated

>Solution :

You’re setting this.board to an array:

if (cleanedBoard.length === 81){
  this.board = cleanedBoard // <= this.board is now an array
  return true
}

So the next time you call validBoardFormat() you end up trying to invoke split on the array, not the string:

let uncleanedBoard = this.board.split('') // this.board is now an array, not a string