[Solved] Identify the problem in this Kotlin code:val y = 15 val res = when (y) { in 1..10 -> "Low" in 11..20 -> "Medium" in 21..30 -> "High" } println(res) | Kotlin

Kotlin - Control Flow as Expressions

Identify the problem in this Kotlin code:

val y = 15
val res = when (y) {
  in 1..10 -> "Low"
  in 11..20 -> "Medium"
  in 21..30 -> "High"
}
println(res)

AMissing else branch causes compilation error

BRanges are incorrect

CVariable y is not initialized

DNo problem, code runs fine

Step-by-Step Solution

Solution:

Step 1: Check completeness of when expression
When expression with argument must be exhaustive or have else branch.
Step 2: No else branch and not all values covered
Values outside 1..30 are not covered, so else is required.
Final Answer:
Missing else branch causes compilation error -> Option A
Quick Check:
Exhaustive when needs else branch = Missing else branch causes compilation error [OK]

Quick Trick: Add else branch if when is not exhaustive [OK]

Common Mistakes:

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