C++ (constructor/destructor order) — determine the exact output produced by construction of multiple objects and their destruction including a nested scope.\n\n#include<iostream.h>\nint val = 0;\nclass CuriousTab {\npublic:\n CuriousTab() { cout << ++val; }\n ~CuriousTab() { cout << val--; }\n};\nint main() {\n CuriousTab objCuriousTab1, objCuriousTab2, objCuriousTab3;\n { CuriousTab objCuriousTab4; }\n return 0;\n}\n\nWhat character sequence is written to stdout?

Introduction / Context:
This program tests your understanding of C++ object lifetime: when constructors run, when destructors run, and the order they print values when a global counter is incremented/decremented. It also includes a temporary object in a nested block to verify scope-bound destruction.

Given Data / Assumptions:

• Global int val starts at 0.
• Constructor prints ++val (pre-increment then print).
• Destructor prints val-- (print current val then post-decrement).
• Three automatic objects in main scope; one additional automatic object in an inner block.

Concept / Approach:
Automatic objects are constructed in declaration order and destroyed in reverse order of construction when their scope ends. An object created inside an inner block is destroyed at the end of that block, before the outer-scope objects are destroyed.

Step-by-Step Solution:

Verification / Alternative check:
Trace val on paper to ensure increments and decrements line up with construction/destruction order.

Why Other Options Are Wrong:

• 1234 / 4321: Ignore destructors or construction order.
• 12341234 / 43211234: Misorder destruction or duplicate patterns.

Common Pitfalls:
Forgetting that the inner object is destroyed before the outer objects, and that destructors run in reverse construction order.

Final Answer:
12344321