split.js

//  ([1,2,3,4,5,6,7],3) === [[1,2,3],[3,4,5],[6,7]]
//  ([1,2,3,5,6,7],1) == [[1],[2],[3],[5],[6],[7]]
function splitArray(lst, n) {
  let result = [];
  for (let i = 0; i < lst.length; i += n) {
    result.push(lst.slice(i, i + n));
  }
  return result;
}

// Test cases
console.log(splitArray([1,2,3,4,5,6,7],3));
console.log(splitArray([1,2,3,5,6,7],1));