1. 6
  1.  

  2. 1

    Wouldn’t it be neat if this was how assignment worked by default?

    • mutable variables
    • immutable values

    Numbers already work this way:

    x = 5
    y = x
    y += 1  // changes y, not x
    

    Why not maps too?

    x = {"a": 1}
    y = x
    y["a"] = 2   // changes y, not x
    

    That last line would be short for y = y.update("a", 2), just like y += 1 is short for y = y + 1.