stairs.js

// stairs = 4
// fun(stairs=4, curr = stairs)

// Start recursion

  // we need to check for base case of recursion.
  // if we hit the base case, then return a empty string.
  // > if hits 0 return blank string

  // base case: curr < 1  return ""

  // I need to work from max to min  4 to 1.  Could also go 1 to 4.

  // => dec
  // 4 (4,4)
  // 3 (4,3)
  // 2 (4,2)
  // 1 (4,1)
  // 0 (4,0) <base Case> no value return; return "" + func()

  // 4 sss# \n
  // 3 ss## \n
  // 2 s### \n
  // 1 ####

  // return string

    // returns curr number of stairs with (stairs - curr) spaces

    // dec curr
    // curr --

    // print spaces
    // spaces = curr

    // print curr steps
    // # x stairs - curr

    // check to see if we need to add a return.  If curr is
    // greater than 0, then there is another line.
    // curr > 0 ? \n : ""  <== really test this, if needs nl

    // call recursion
    // >  call fun(stairs, curr)

// End recursion

const fun = (stairs, curr = stairs) => {
  // base case
  if (curr < 1) return "";

  // dec curr
  curr--;

  return (
    // print spaces
    " ".repeat(curr) +
    
    // print curr steps
    "#".repeat(stairs - curr) +
    
    // check for newline
    (curr > 0 ? "\n" : "") +
    
    // recursion!!
    fun(stairs, curr)
  );
};

console.log(fun(4));