Swift - Variables and Constants
Which of the following Swift variable declarations correctly uses type inference?
Which of the following Swift variable declarations correctly uses type inference?
easy📝 Conceptual Q2 of 15
Step-by-Step Solution
Solution:
Step 1: Analyze each declaration
let greeting = "Hello, world!" assigns a String literal to a constant without explicit type, so type inference deduces String.Step 2: Check for type mismatches
Options B and C assign String values to Int and Double types explicitly, which is invalid. var isActive = true as String tries to cast Bool to String incorrectly.Final Answer:
let greeting = "Hello, world!" -> Option AQuick Check:
Correct type inference matches assigned value type [OK]
Quick Trick: Match value type with inferred type [OK]
Common Mistakes:
- Assigning String to Int or Double variables
- Incorrect type casting
- Confusing explicit type with inferred type
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