Object Spread
π¨βπΌ Excellent! You've mastered immutable object updates with spread.
π¦ Key insights:
- Spread creates shallow copies - Properties are copied, but nested objects are still references
- Order matters - Later spreads override earlier properties
- Nested updates need nested spreads - Each level needs its own
...
This pattern is fundamental to React:
// Updating state immutably
setState((prev) => ({ ...prev, count: prev.count + 1 }))
// Updating nested state
setState((prev) => ({
...prev,
user: { ...prev.user, name: newName },
}))
Without spread, you'd have to manually copy every property. Spread makes
immutable updates concise and readable.