Consider struct test { int x; double y; char z; }; What is the minimum size of this structure (assuming 4-byte int, 8-byte double)?

The correct answer is D: 24 bytes. Due to padding: int (4) + padding (4) + double (8) + char (1) + padding (3) = 24 bytes. The structure aligns to the largest member size.

In the expression: int arr[5]; int *p = arr; What does p + 2 represent?

The correct answer is B: Address of arr[2]. Pointer arithmetic scales by data type size. p + 2 moves 2 * sizeof(int) bytes forward, pointing to arr[2].

Which statement about #define is TRUE?

The correct answer is B: Macros do not allocate memory at runtime. Macros are purely textual substitutions performed by the preprocessor at compile time, not at runtime. They don't allocate memory themselves.

In C programming, when you declare a variable as 'const int x = 5;', what happens if you try to modify it within the program?

The correct answer is B: The compiler will generate a compilation error and prevent modification. The 'const' keyword creates a read-only variable. Once initialized, attempting to modify a const variable results in a compilation error (error: assignment of read-only variable). This is enforced at compile-time, not runtime.

What is the size of a 'long long int' variable in C on a 64-bit system?

The correct answer is B: 8 bytes. A 'long long int' is guaranteed to be at least 64 bits (8 bytes) by the C99 standard on all systems including 64-bit architectures.

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C Programming

C language from basics to advanced placement prep

197 Q 10 Topics Take Mock Test

Difficulty: All Easy Medium Hard 181–190 of 197

Topics in C Programming

All Basics & Syntax 86 Data Types & Variables 97 Control Flow 100 Functions 99 Arrays & Strings 100 Pointers 99 Structures & Unions 100 File Handling 100 Dynamic Memory 98 Preprocessor 99

Q.181 Hard Basics & Syntax

What is the output of: float x = 5/2; printf("%f", x);

A 2.5

B 2.0

C 2.500000

D Error

Correct Answer: B. 2.0

EXPLANATION

5/2 is integer division (not float division), so result is 2 (integer), then converted to 2.0 (float).

Test

Q.182 Hard Basics & Syntax

Which of the following about function pointers in C is correct?

A int *func();

B int (*func)();

C int func*();

D int *func*();

Correct Answer: B. int (*func)();

EXPLANATION

int (*func)(); declares a pointer to a function that returns int. Option A declares a function returning pointer to int.

Test

Q.183 Hard Basics & Syntax

What will be the output of: int a = 1; int b = 2; a = a + b; b = a - b; a = a - b; printf("%d %d", a, b);

A 1 2

B 2 1

C 3 1

D 1 3

Correct Answer: B. 2 1

EXPLANATION

Initial: a=1, b=2. After step 1: a=3, b=2. After step 2: a=3, b=1. After step 3: a=2, b=1. Output is '2 1'.

Test

Q.184 Hard Basics & Syntax

What is the scope of a variable declared inside a block with 'static'?

A Global scope

B Function scope

C Block scope with static storage duration

D File scope

Correct Answer: C. Block scope with static storage duration

EXPLANATION

A static variable declared in a block has block scope but static storage duration, persisting between function calls.

Test

Q.185 Hard Basics & Syntax

What is the output of: int x = 5; int y = ++x + x++;

A y = 12

B y = 13

C Undefined behavior

D Compilation error

Correct Answer: C. Undefined behavior

EXPLANATION

This involves undefined behavior due to modification of x multiple times without intervening sequence points.

Test

Q.186 Hard Basics & Syntax

What is the result of: int x = 10; int y = x++ + x++;

A y = 20

B y = 21

C y = 22

D Undefined behavior

Correct Answer: D. Undefined behavior

EXPLANATION

Multiple post-increments without sequence points lead to undefined behavior.

Test

Q.187 Hard Basics & Syntax

What will be the output of: int x = 5; printf("%d", x++ + ++x);

A 11

B 12

C 10

D Undefined behavior

Correct Answer: D. Undefined behavior

EXPLANATION

This exhibits undefined behavior due to multiple modifications of the same variable 'x' without intervening sequence points.

Test

Q.188 Hard Basics & Syntax

Which of the following best describes the 'register' storage class in modern C compilers?

A Guarantees storage in CPU register

B A hint to the compiler to optimize variable storage; compiler may ignore it

C Forces the variable to be global

D Automatically allocates memory on the stack

Correct Answer: B. A hint to the compiler to optimize variable storage; compiler may ignore it

EXPLANATION

The 'register' keyword is a hint for compiler optimization. Modern compilers often ignore it as they have sophisticated optimization strategies.

Test

Q.189 Hard Basics & Syntax

What is the output of: printf("%d", (int)3.7);?

A 3.7

B 3

C 4

D Error

Correct Answer: B. 3

EXPLANATION

Type casting (int)3.7 truncates the decimal part, converting 3.7 to 3. The fractional part is discarded.

Test

Q.190 Hard Basics & Syntax

Consider a function declared as 'static int func()'. What is the scope of this function?

A Global scope across all files

B Limited to the current file only

C Only within the function where it's declared

D Limited to the current block

Correct Answer: B. Limited to the current file only

EXPLANATION

When 'static' is applied to a function at file scope, it restricts the function's visibility to that translation unit (file) only.

Test

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