C#.NET — Choose the correct way to declare and initialize a variable of the struct Emp. struct Emp { private string name; private int age; private float sal; } Which one of the following single-line or two-line snippets correctly declares a variable and initializes it?

Difficulty: Easy

Correct Answer: Emp e = new Emp();

Explanation:


Introduction / Context:
This question asks for a correct declaration/initialization pattern for a user-defined struct Emp. For parameterless construction of a struct, C# permits using new Emp() to create a zero-initialized instance, invoking the implicit parameterless initializer logic for value types (unless an explicit parameterized constructor is defined).


Given Data / Assumptions:

  • Emp is a struct (value type) with three private fields.
  • We want one correct way to both declare and initialize a variable.


Concept / Approach:
For value types, you can either declare a variable and then assign with new Emp(), or perform both in one statement. The keyword new zero-initializes all fields. Syntax must include parentheses when calling the parameterless initializer for a struct. The distractors either omit parentheses, reverse assignment, or use signatures that do not compile in C#.


Step-by-Step Solution:

Check “Emp e();” — in C# this is parsed like a parameterless method declaration in certain contexts and is not a variable definition; reject. Check “Emp e = new Emp;” — missing parentheses; invalid for a struct initializer call. Check “Emp e; e = new Emp;” — again missing parentheses; invalid. Check “Emp e = new Emp();” — valid: declares e and initializes it in one line. Check “new Emp() = e;” — reversed assignment; illegal.


Verification / Alternative check:
If desired, the two-line valid equivalent is: Emp e; e = new Emp(); which also compiles and creates a zero-initialized struct instance.


Why Other Options Are Wrong:

  • A: Not a variable definition in C#.
  • B/C: Missing parentheses after Emp; does not compile.
  • E: Assignment direction is invalid; left side must be a variable.


Common Pitfalls:
Forgetting parentheses when using new with structs; confusing C# syntax with C/C++ forms; misreading “Emp e();” as a variable instead of a method-like form.


Final Answer:
Emp e = new Emp();

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