What is the main purpose of lazy initialization and in what situations is it used?

Lazy initialization is the deferred creation or initialization of an object or resource until the moment of its first use. The main goal is to optimize resource usage and improve performance by avoiding the costs of creating objects that may not be needed.

It is used in situations where:

• Initialization is resource-intensive (e.g., loading data from a network or database).
• The object may not be needed during the program's execution.
• To speed up application startup by postponing heavy operations.

In Swift, the lazy keyword is used for lazy initialization:

class DataManager {
    lazy var data = loadData()

    func loadData() -> [String] {
        print("Loading data")
        return ["item1", "item2"]
    }
}

let manager = DataManager() // data is not yet loaded
print(manager.data) // data loading occurs here

Thus, data is initialized only upon first access.