1 number
   2 5.859874482048838
   3 string
   4 hello, world
   5 string
   6 E is 2.718281828459045
   7 string
   8 3.141592653589793 is PI
   9 number
  10 NaN
  11 number
  12 NaN
  13 number
  14 90.21
  15 number
  16 47.69
  17 string
  18 hello, obj2.toString
  19 string
  20 obj2.toString hello