[Solved] What is the problem with this Kotlin code?var count: Int? = 5 count = null val total: Int = count + 10 | Kotlin

Kotlin - Null Safety

What is the problem with this Kotlin code?

var count: Int? = 5
count = null
val total: Int = count + 10

AThere is no problem; code compiles and runs fine

BVariable count cannot be assigned null because it is not nullable

CThe variable total should be declared as nullable Int

DCannot perform arithmetic on a nullable Int without safe call or non-null assertion

Step-by-Step Solution

Solution:

Step 1: Identify variable types
count is declared as Int?, meaning it can be null.
Step 2: Analyze the expression
Adding count + 10 is invalid because count might be null, and Kotlin does not allow arithmetic on nullable types without explicit handling.
Step 3: Correct approach
Use safe call or non-null assertion, e.g., count?.plus(10) or count!! + 10 if sure not null.
Final Answer:
Cannot perform arithmetic on a nullable Int without safe call or non-null assertion -> Option D
Quick Check:
Nullable Int requires safe handling before arithmetic [OK]

Quick Trick: Nullable Int needs safe call or !! before arithmetic [OK]

Common Mistakes:

MISTAKES

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