The second hardest challenge listed in the “easy” section of Coderbyte.

vowelSquare.js

function vowelSquare(matrix) {
  
  let vowels = {
    a: 1,
    e: 1,
    i: 1,
    o: 1,
    u: 1
  }
  
  let rows = matrix.length
  let cols = matrix[0].length
  
  for (let i = 0; i < rows - 1; i++) {
    for (let j = 0; j < cols - 1; j++) {
      
      if (matrix[i][j] in vowels
        && matrix[i][j+1] in vowels
        && matrix[i+1][j] in vowels
        && matrix[i+1][j+1] in vowels) {

        return `${i}-${j}`
      }
    }
  }
  
  return 'not found'
}