
C Language Structures & Unions - Practice Questions 2026
Course Description
Master C Language Structures and Unions: javascript error handling practice questions 2026
Welcome to the most comprehensive practice exam suite designed specifically to help you master C Language Structures and Unions. Whether you are a student preparing for academic exams or a developer aiming to sharpen your systems programming skills, these practice tests provide the rigorous training you need.
Why Serious Learners Choose These Practice Exams
Serious learners understand that watching a video is not the same as writing code. Mastery over C requires an intimate understanding of memory layout, padding, and data alignment. This course is designed to challenge your logic and force you to think like a compiler. By practicing with these exams, you ensure that you aren't just memorizing syntax, but truly grasping how C manages complex data types.
Course Structure
This practice suite is divided into logical tiers to ensure a smooth learning curve:
Basics / Foundations: Focuses on the syntax of defining structures and unions. You will practice declaring variables, initializing members, and accessing them using the dot operator.
Core Concepts: Delves into the fundamental differences between structures and unions. This section tests your knowledge of how memory is allocated for each member and the implications of sharing memory in a union.
Intermediate Concepts: Covers nested structures, arrays of structures, and passing complex types to functions. You will also explore pointers to structures and the arrow (->) operator.
Advanced Concepts: Challenges you with memory alignment, structure padding, and bit-fields. These are critical topics for low-level programming where every byte of memory counts.
Real-world Scenarios: Presents problems modeled after actual engineering tasks, such as defining network packet headers, hardware registers, and file metadata formats.
Mixed Revision / Final Test: A comprehensive simulation of a professional exam. This final tier mixes all previous topics to test your ability to switch context and solve complex problems under time pressure.
Question 1
What will be the output of the following C code?
C
struct Data {
int i;
char c;
};
struct Data d = {10, 'A'};
struct Data *ptr = &d;
printf("%d", ptr->i);
Option 1: 10
Option 2: A
Option 3: Garbage Value
Option 4: Compiler Error
Option 5: Segmentation Fault
Correct Answer: Option 1
Correct Answer Explanation: In C, when you have a pointer to a structure, you access its members using the arrow operator (->). Here, ptr points to the structure d. Therefore, ptr->i correctly accesses the integer member i, which was initialized to 10.
Wrong Answers Explanation:
Option 2: 'A' is the value of the member c, not i.
Option 3: The variable is explicitly initialized to 10, so there is no reason for a garbage value.
Option 4: The syntax is perfectly valid C code; there are no errors.
Option 5: The pointer ptr is correctly assigned the address of d, so accessing it does not cause a segmentation fault.
Question 2
In a Union defined as union Shared { int a; char b; };, if you assign u.a = 65;, what will be the value of u.b on a typical system?
Option 1: 0
Option 2: 65
Option 3: 'A'
Option 4: Undefined
Option 5: Compiler Error
Correct Answer: Option 3
Correct Answer Explanation: In a union, all members share the same memory location. The integer 65 corresponds to the ASCII value of the character 'A'. Since a and b share the same starting address, assigning 65 to a effectively places that bit pattern into the shared memory, which b interprets as 'A'.
Wrong Answers Explanation:
Option 1: Memory is shared, so b will not remain 0 if a is modified.
Option 2: While the numeric value is 65, the type of b is char, so it is interpreted as the character 'A'.
Option 4: While the behavior of unions can be platform-dependent, the basic sharing of the first byte is well-defined in this context.
Option 5: This is standard union usage and is perfectly legal in C.
Key Features of This Course
You can retake the exams as many times as you want.
This is a huge original question bank.
You get support from instructors if you have questions.
Each question has a detailed explanation.
Mobile-compatible with the Udemy app.
30-days money-back guarantee if you are not satisfied.
We hope that by now you are convinced! And there are a lot more questions inside the course.
Save $19.99 - Limited time offer
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