Kotlin - Null Safety
Given a map with nullable values:
val map: Map = mapOf("a" to "apple", "b" to null, "c" to "cat")
How do you create a new map excluding entries with null values using Kotlin?
Given a map with nullable values: val map: Map = mapOf("a" to "apple", "b" to null, "c" to "cat") How do you create a new map excluding entries with null values using Kotlin?
hard📝 Application Q9 of 15
Step-by-Step Solution
Solution:
Step 1: Understand the map and filtering goal
The map has nullable values. We want to exclude entries where the value is null.Step 2: Use filterValues with a null check
filterValues { it != null } returns a map with only entries whose values are not null.Final Answer:
val filtered = map.filterValues { it != null } -> Option BQuick Check:
filterValues filters map entries by value condition [OK]
Quick Trick: Use filterValues { it != null } to exclude null values [OK]
Common Mistakes:
MISTAKES- Filtering keys instead of values
- Using mapValues with !! risking exceptions
- Filtering for null values instead of excluding them
Master "Null Safety" in Kotlin
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