[Solved] Identify the error in this Swift code using nil coalescing:let x: Int? = nil let y: Int = 3 let z = x ?? y ?? 5 print(z) | Swift

Swift - Operators and Expressions

Identify the error in this Swift code using nil coalescing:

let x: Int? = nil
let y: Int = 3
let z = x ?? y ?? 5
print(z)

Ax must be non-optional

BNo error, code runs fine

Cy must be optional to use ??

DCannot use ?? with non-optional y

Step-by-Step Solution

Solution:

Step 1: Understand the types involved in nil coalescing
The operator ?? requires the right side to be the same type as the optional or a non-optional fallback value.
Step 2: Analyze the expression x ?? y ?? 5
Here, x is Int?, y is Int, but y ?? 5 is invalid because y is not optional, so you cannot use ?? on it.
Final Answer:
Cannot use ?? with non-optional y -> Cannot use ?? with non-optional y
Quick Check:
Right side of ?? must be optional or value [OK]

Quick Trick: Right side of ?? must be optional or value, not non-optional with ?? [OK]

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