[Solved] Find the issue in this code:List list = new ArrayList(); list.add(10); int sum = 0; for(Integer num : list) { sum += num; } System.out.println(sum); | Java

Java - Wrapper Classes

Find the issue in this code:

List list = new ArrayList<>();
list.add(10);
int sum = 0;
for(Integer num : list) {
    sum += num;
}
System.out.println(sum);

ACode works and prints 10

BRuntime NullPointerException

CCompilation error due to incompatible types

DInfinite loop occurs

Step-by-Step Solution

Solution:

Step 1: Check autoboxing and unboxing in loop
Adding 10 to list autoboxes int to Integer. In the loop, num unboxes to int for addition.
Step 2: Verify code correctness
All types match, no nulls, so sum accumulates 10 and prints correctly.
Final Answer:
Code works and prints 10 -> Option A
Quick Check:
Autoboxing and unboxing work seamlessly in collections [OK]

Quick Trick: Autoboxing works smoothly with collections and loops [OK]

Common Mistakes:

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