Challenge 2 — Solution

Task: Create const settings = { theme: "dark", display: {
brightness: 80 } }. Create a shallow copy with spread, change the
copy's display.brightness to 50, then log the original's
display.brightness to demonstrate the shallow-copy bug from this
chapter.

const settings = { theme: "dark", display: { brightness: 80 } };

const copy = { ...settings };
copy.display.brightness = 50;

console.log(settings.display.brightness);


Expected output:

50


Notes:
- This is the shallow-copy bug demonstrated directly: { ...settings }
  copied the theme property (a primitive) independently, but display
  is an object, so only the REFERENCE to it was copied — copy.display
  and settings.display still point at the exact same nested object.
- Changing copy.display.brightness therefore also changes
  settings.display.brightness, even though settings was never
  touched directly by name.
- This is exactly the situation structuredClone (Challenge 3) is
  designed to prevent.