Where in the project or system are constant values usually defined?

Constant values in iOS projects are usually defined in separate files or structures to centralize them and facilitate maintenance. Commonly used methods include:

• A Constants.swift file where a struct or enum with static let constants is declared.
• Using UserDefaults for storing settings, although this is not exactly "constant" values.
• In some cases — plist files for configurations.

Example of defining constants in Constants.swift:

struct Constants {
    static let apiBaseUrl = "https://api.example.com"
    static let timeoutInterval: TimeInterval = 30
}

This approach simplifies changing values and prevents code duplication.