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User object properties and their types:
user.id: 1 (number)
user.name: Alice (string)
user.email: alice@example.com (string)
user.active: true (boolean)

Using string methods on name property:
Uppercase: ALICE
Length: 5

Nested object properties:
user.details.age: 30 (number)
user.details.address.city: New York (string)
user.details.address.country: USA (string)

Using methods on nested properties:
Age (fixed decimal): 30
City (lowercase): new york

In TypeScript, accessing non-existent properties would cause compile-time errors:
user.age                  // Error: Property 'age' does not exist
user.details.name         // Error: Property 'name' does not exist
user.details.address.zip  // Error: Property 'zip' does not exist