Quick Answer

Optional chaining and multiple unwrapping

Understanding the Issue

Swift provides sophisticated Optional handling including chaining, map/flatMap operations, and combining multiple unwraps in single if-let statements.

The Problem

This code demonstrates the issue:

Swift Error 
// Problem: Nested optional binding
if let user = currentUser {
    if let address = user.address {
        if let street = address.street {
            print(street)
        }
    }
}

The Solution

Here's the corrected code:

Swift Fixed 
// Solution 1: Optional chaining
if let street = currentUser?.address?.street {
    print(street)
}

// Solution 2: Multiple unwrapping
if let user = currentUser, let address = user.address {
    print(address.city)
}

Key Takeaways

Combine Optional operations to flatten nested conditionals.