Kotlin - Null Safety
What will be the output of this Kotlin code?
var number: Int? = 10 number = null println(number?.plus(5) ?: "No value")
What will be the output of this Kotlin code?
medium📝 Predict Output Q5 of 15
Step-by-Step Solution
Solution:
Step 1: Analyze nullable variable and safe call
number is null, so number?.plus(5) returns null.Step 2: Apply Elvis operator fallback
Since the safe call returns null, the expression prints "No value".Final Answer:
No value -> Option AQuick Check:
Safe call with null triggers fallback [OK]
Quick Trick: Safe calls return null if variable is null, use ?: for fallback [OK]
Common Mistakes:
MISTAKES- Expecting 15 despite null value
- Thinking null is printed
- Assuming exception is thrown
Master "Null Safety" in Kotlin
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