You want to assign a grade based on a score using when as an expression. Which code correctly returns "A" for scores 90 and above, "B" for 80-89, "C" for 70-79, and "F" otherwise?
hard📝 Application Q15 of 15
Kotlin - Control Flow as Expressions
You want to assign a grade based on a score using when as an expression. Which code correctly returns "A" for scores 90 and above, "B" for 80-89, "C" for 70-79, and "F" otherwise?
Dval grade = when {
in 90..100 -> "A"
in 80..89 -> "B"
in 70..79 -> "C"
else -> "F"
}
Step-by-Step Solution
Solution:
Step 1: Understand when with condition expressions
val grade = when {
score >= 90 -> "A"
score >= 80 -> "B"
score >= 70 -> "C"
else -> "F"
} uses when without argument and conditions like score >= 90, which is valid and clear for ranges.
Step 2: Check other options for errors
val grade = when (score) {
in 90..100 -> "A"
in 80..89 -> "B"
in 70..79 -> "C"
else -> "F"
} is correct syntax but uses ranges; val grade = when (score) {
score >= 90 -> "A"
score >= 80 -> "B"
score >= 70 -> "C"
else -> "F"
} incorrectly uses conditions inside when(score) which expects values, not conditions; val grade = when {
in 90..100 -> "A"
in 80..89 -> "B"
in 70..79 -> "C"
else -> "F"
} uses in without variable, which is invalid.
Final Answer:
val grade = when {
score >= 90 -> "A"
score >= 80 -> "B"
score >= 70 -> "C"
else -> "F"
} -> Option C
Quick Check:
Use when without argument for conditions [OK]
Quick Trick:Use when without argument for condition checks [OK]
Common Mistakes:
MISTAKES
Using conditions inside when(variable)
Omitting variable in range checks
Misplacing in keyword
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