B CompE Bachelor of Computer Engineering Bachelor of Computer Engineering C Language 5

Question 1

What is the correct way to open a file for both reading and writing in binary mode in C?

Accepted Answer

fopen("file", "r+b")

Answer

The mode `"r+b"` opens an existing binary file for both reading and writing without truncating it.

Question 2

Which of the following C expressions evaluates the absolute value of an integer without using the standard library?

Accepted Answer

x < 0 ? -x : x

Answer

The ternary expression `x < 0 ? -x : x` returns `-x` when `x` is negative and `x` otherwise, correctly computing absolute value.

Question 3

In C, what is the effect of declaring a local variable inside a block `{ }` nested within a function?

Accepted Answer

It has block scope and is destroyed when execution leaves the block

Answer

Local variables declared inside a nested block have block scope; they are allocated on the stack when the block is entered and destroyed when it is exited.

Question 4

What does the `realloc` function do in C?

Accepted Answer

Allocates a new block and frees the old one automatically while preserving existing data up to the smaller size

Answer

`realloc` resizes a previously allocated block, copies data up to the minimum of old and new sizes, and may return a new pointer if the block was moved.

Question 5

What is the role of the linker in C program compilation?

Accepted Answer

Resolves external references and combines object files into an executable

Answer

The linker combines compiled object files, resolves symbol references (like function calls across files), and produces the final executable or library.

B CompE Bachelor of Computer Engineering Practice Test

B CompE Bachelor of Computer Engineering Practice Test

B CompE Bachelor of Computer Engineering Bachelor of Computer Engineering C Language 5