Kotlin - Null Safety
How can you safely cast a nullable Any? variable to String? and provide a default value if the cast fails?
val obj: Any? = getObject() val str: String = (obj ___) ?: "default"
How can you safely cast a nullable Any? variable to String? and provide a default value if the cast fails?
hard📝 Application Q9 of 15
Step-by-Step Solution
Solution:
Step 1: Use safe cast to nullable String
The safe castas?returns a nullable String or null if cast fails.Step 2: Use Elvis operator for default
The Elvis operator?:provides "default" if the cast returns null.Final Answer:
as? String -> Option BQuick Check:
Safe cast with default uses 'as?' and '?:' = A [OK]
Quick Trick: Use 'as?' with '?:' to provide default on cast failure [OK]
Common Mistakes:
MISTAKES- Using unsafe cast causing exceptions
- Incorrect nullable type syntax
- Omitting default value for null
Master "Null Safety" in Kotlin
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