StairCase.js

function StairCase(n) {

  var printLine = function(y, t){
    var line = '';
    for (var j = 0; j <= t; j++) {
      if (j < y) {
        line += ' ';
      } else if (j > y){
        line += '#';
      }
    }
    return line;
  };

  var stair = '';
  for (var i = n-1; i >= 0; i--) {
    stair += printLine(i, n) + '\n';
  }
  return stair;
}

var stair = StairCase(32);
console.log(stair);