Kotlin - Null Safety
Given
var input: String? = "123", which code safely converts it to an integer or returns 0 if null or invalid?Given var input: String? = "123", which code safely converts it to an integer or returns 0 if null or invalid?
hard📝 Application Q9 of 15
Step-by-Step Solution
Solution:
Step 1: Handle nullable input safely
Use safe call?.to avoid callingtoInt()on null.Step 2: Provide default value with elvis operator
?: 0returns 0 if the left side is null.Final Answer:
val number = input?.toInt() ?: 0 -> Option BQuick Check:
Safe call plus elvis operator handles null and invalid safely [OK]
Quick Trick: Use ?. with ?: to safely convert nullable strings [OK]
Common Mistakes:
MISTAKES- Using !! risking exceptions on null
- Calling toInt() directly on nullable
- Ignoring default value for null cases
Master "Null Safety" in Kotlin
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