What is the output of this Java code?

medium📝 Predict Output Q13 of 15

Java - Wrapper Classes

Integer a = 5;
int b = a + 10;
System.out.println(b);

ANullPointerException

B510

CCompilation error

D15

Step-by-Step Solution

Solution:

Step 1: Understand unboxing in expression
Variable 'a' is Integer object; adding 10 triggers unboxing 'a' to int 5.
Step 2: Calculate the sum and print
5 + 10 = 15, so output is 15 printed.
Final Answer:
15 -> Option D
Quick Check:
Unboxing Integer 5 + 10 = 15 [OK]

Quick Trick: Unboxing happens automatically in arithmetic expressions [OK]

Common Mistakes:

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