Given val doubles = listOf(2.3, 5.7, 9.1), which Kotlin code correctly creates a list of Ints by explicitly converting each Double?
hard📝 Application Q8 of 15
Kotlin - Data Types
Given val doubles = listOf(2.3, 5.7, 9.1), which Kotlin code correctly creates a list of Ints by explicitly converting each Double?
Aval ints = doubles.map { it.toInt() }
Bval ints = doubles.map { it as Int }
Cval ints = doubles.map { it.toDouble().toInt() }
Dval ints = doubles.map { it.toIntOrNull() }
Step-by-Step Solution
Solution:
Step 1: Understand map transformation
Use map to transform each element in the list.
Step 2: Use explicit conversion
toInt() converts Double to Int explicitly.
Step 3: Evaluate options
val ints = doubles.map { it.toInt() } correctly uses toInt(). val ints = doubles.map { it as Int } uses unsafe cast, causing runtime error. val ints = doubles.map { it.toDouble().toInt() } is redundant. val ints = doubles.map { it.toIntOrNull() } returns nullable Ints, which is incorrect here.
Final Answer:
val ints = doubles.map { it.toInt() } -> Option A
Quick Check:
Use map with toInt() for explicit conversion [OK]
Quick Trick:Use map { it.toInt() } for list conversion [OK]
Common Mistakes:
MISTAKES
Using unsafe casts instead of explicit conversion
Confusing nullable conversions with toIntOrNull()
Redundant conversions like toDouble().toInt()
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