Predict the output of the following C#.NET code (pay close attention to post-increment and pre-increment on the same variable): int i, j = 1, k; for (i = 0; i < 5; i++) { k = j++ + ++j; Console.Write(k + " "); }

Introduction / Context:
This question tests evaluation order and side effects of the post-increment (x++) and pre-increment (++x) operators in C#. Understanding how the same variable changes within one expression is vital to avoid subtle bugs.

Given Data / Assumptions:

• Initial values: j = 1; loop executes 5 times.
• Expression: k = j++ + ++j inside the loop.
• C# left-to-right operand evaluation for the + operator.

Concept / Approach:
For j++: the value used is the old value, then j increments by 1. For ++j: j is first incremented, then the new value is used. The binary + evaluates its left operand first, then right operand, applying side effects in that order.

Step-by-Step Solution:

Verification / Alternative check:
Insert diagnostic prints after each operand or run in a debugger to observe j's changes stepwise.

Why Other Options Are Wrong:
They reflect misordered evaluation or arithmetic sequences not produced by this side-effect pattern.

Common Pitfalls:
Assuming unspecified order of evaluation (in C#, + evaluates left to right) or misinterpreting pre/post increment semantics.

Final Answer:
4 8 12 16 20