iOS Swift - Lists and Data Display
Why does this code cause a compile error?
struct Book: Identifiable {
var id: Int
var title: String
}
let b = Book(title: "Swift Guide")
Why does this code cause a compile error? struct Book: Identifiable { var id: Int var title: String } let b = Book(title: "Swift Guide")
medium📝 Debug Q7 of 15
Step-by-Step Solution
Solution:
Step 1: Check struct initialization
Struct has two properties:idandtitle, both non-optional.Step 2: Analyze initializer call
Initializer call provides onlytitle, missingid, causing compile error.Final Answer:
Missing id parameter in initializer call. -> Option AQuick Check:
All non-optional properties must be initialized = A [OK]
Quick Trick: Initialize all non-optional properties when creating struct [OK]
Common Mistakes:
- Assuming missing id is allowed
- Thinking title must be optional
- Confusing struct and class rules
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