Rotate 2D array matrix to the left (one step at a time)

rotateMatrixToLeft.js

function rotateMatrix(rowCount, colCount, matrix) {
  let row = 0;
  let col = 0;
  let prev;
  let curr;

  /*
    row - Starting row index
    rowCount - ending row index
    col - starting column index
    colCount - ending column index
    i - iterator
    */
  while (row < rowCount && col < colCount) {
    if (row + 1 === rowCount || col + 1 === colCount) break;

    // Store the first element of next
    // row, this element will replace
    // first element of current row

    // prev = matrix[row + 1][col];
    prev = matrix[row + 1][colCount - 1];

    // Move elements of first row
    // from the remaining rows
    for (let i = colCount - 1; i >= col; i--) {
      curr = matrix[row][i];
      matrix[row][i] = prev;
      prev = curr;
    }
    row++;

    // Move elements of first column
    // from the remaining columns
    for (let i = row; i < rowCount; i++) {
      curr = matrix[i][col];
      matrix[i][col] = prev;
      prev = curr;
    }
    col++;

    // Move elements of last row
    // from the remaining rows
    if (row < rowCount) {
      for (let i = col; i < colCount; i++) {
        curr = matrix[rowCount - 1][i];
        matrix[rowCount - 1][i] = prev;
        prev = curr;
      }
    }
    rowCount--;

    // Move elements of last column
    // from the remaining rows
    if (col < colCount) {
      for (let i = rowCount - 1; i >= row; i--) {
        curr = matrix[i][colCount - 1];
        matrix[i][colCount - 1] = prev;
        prev = curr;
      }
    }
    colCount--;
  }

  return matrix;
}