Kotlin - Collections Fundamentals
What is the output of this Kotlin code?
val map = mapOf("x" to 10, "y" to 20)
println(map["x"])
println(map["z"])What is the output of this Kotlin code?
medium📝 Predict Output Q13 of 15
Step-by-Step Solution
Solution:
Step 1: Access existing key "x"
map["x"] returns 10 because "x" is a key with value 10.Step 2: Access non-existing key "z"
map["z"] returns null because "z" is not in the map.Final Answer:
10\nnull -> Option BQuick Check:
Existing key returns value, missing key returns null [OK]
Quick Trick: map[key] returns value or null if key missing [OK]
Common Mistakes:
MISTAKES- Expecting 0 instead of null for missing key
- Confusing values of different keys
- Assuming map is mutable and can add keys
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