PascalTriangle created by svngoku - https://repl.it/@svngoku/PascalTriangle

main.js

/* Pascal Triangle II */

const getItem = (row,j) => {
  if (j < 0 || j >= row.length) {
    return 0;
  }
  return row[j];
}

const getRow = (rowIndex) => {
  let row = [1];
  for(let i = 0; i < rowIndex; ++i) {
    let newRow = [];
    for(let j = 0; j <= i; ++j) {
      let digit = getItem(row, j-1) + getItem(row, j);
      newRow.push(digit);
    }
    row = newRow;
  }
  return row;
};



console.log(getRow(3))