What techniques and approaches can improve the efficiency of Swift code?

To improve the efficiency of Swift code, the following techniques can be used:

• Using value types (structures and enumerations) instead of classes to reduce memory management overhead.
• Optimizing loops and algorithms by avoiding unnecessary operations and copies.
• Using lazy properties for deferred initialization to avoid creating objects prematurely.
• Minimizing the use of optionals when possible to avoid extra checks.
• Utilizing built-in functions and methods of the standard library that are optimized.
• Profiling code with Instruments to identify bottlenecks.

Example of using a lazy property:

class DataLoader {
    lazy var data = loadData()

    func loadData() -> [String] {
        // heavy loading operation
        return ["item1", "item2"]
    }
}

Here, data will only load upon the first access, saving resources.