C#.NET — Evaluate the expression and predict the output. int x = 1; float y = 1.1f; short z = 1; Console.WriteLine((float)x + y * z - (x += (short)y));

Difficulty: Medium

Correct Answer: 0.1

Explanation:


Introduction / Context:
This problem tests operator precedence, implicit/explicit conversions, and evaluation order in C#.



Given Data / Assumptions:

  • x = 1 (int), y = 1.1f (float), z = 1 (short).
  • Expression: (float)x + y * z - (x += (short)y)
  • C# evaluates subexpressions left-to-right and applies standard numeric promotions.


Concept / Approach:
Key points: casting y to short truncates toward zero (1.1f → 1). The compound assignment x += value both updates x and yields the updated value. Multiplication has higher precedence than addition/subtraction, but subexpression evaluation still respects left-to-right side effects.



Step-by-Step Solution:

Start: x = 1, y = 1.1f, z = 1. Evaluate (float)x → 1.0f (uses current x = 1). Evaluate y * z → 1.1f * 1 = 1.1f. Compute (x += (short)y): (short)y → 1; x becomes 1 + 1 = 2; the subexpression value is 2. Total: 1.0f + 1.1f - 2 = 0.1f.


Verification / Alternative check:
Running the code prints 0.1 (subject to usual floating formatting). Any difference implies a misunderstanding of side-effect timing.



Why Other Options Are Wrong:
They assume wrong cast behavior, precedence, or that x's new value is used in earlier subexpressions (it is not).



Common Pitfalls:
Thinking (short)1.1f rounds to 2 (it truncates to 1), or believing the x += side effect affects (float)x computed earlier.



Final Answer:
0.1

More Questions from Datatypes

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion