[Solved] Find the error in this code:int a = 5; Integer b = null; int c = a + b; — Ans: NullPointerException at runtime | Java

Java - Wrapper Classes

Find the error in this code:

int a = 5;
Integer b = null;
int c = a + b;

Ac equals 0

BCompilation error: cannot add int and Integer

Cc equals 5

DNullPointerException at runtime

Step-by-Step Solution

Solution:

Step 1: Analyze addition with null Integer
Variable b is null, unboxing b causes NullPointerException.
Step 2: Confirm runtime behavior
Code compiles but throws exception when adding int and null Integer.
Final Answer:
NullPointerException at runtime -> Option D
Quick Check:
Unboxing null in arithmetic throws exception [OK]

Quick Trick: Adding null wrapper to int causes NullPointerException [OK]

Common Mistakes:

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