How to be sure to get an item from an array, without undefined

I have a list of positions, I want to return the position that has given coordinates but Array.find can return undefined. How do I make sure I have everything I need.

type Direction = 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8  type File = Direction  type Rank = Direction    type Pos = [Direction, Direction]    const dirs: Direction[] = [1,2,3,4,5,6,7,8]    const files: File[] = dirs  const ranks: Rank[] = dirs  const poss: Pos[] = files.flatMap(file =>    ranks.map(rank => pos(file, rank)));    function pos(file: Direction, rank: Direction): Pos {    return poss.find(([_file, _rank]) => {      file === _file && rank === _rank;    });  }  

https://stackoverflow.com/questions/66609150/how-to-be-sure-to-get-an-item-from-an-array-without-undefined March 13, 2021 at 09:04AM