Mastering C Programming Concepts

What is a pointer in C and how is it used?

• A pointer in C is a special data type that can only hold integer values.

• A pointer in C is a type of function that returns a value.

• A pointer in C is a variable that holds the address of another variable, enabling direct memory access and manipulation.

• A pointer in C is a variable that stores a string of characters.

Explain the difference between stack and heap memory.

• Stack memory is for static allocation and is faster; heap memory is for dynamic allocation and is larger but slower.

• Stack memory is larger and slower; heap memory is for static allocation and is faster.

• Heap memory is for static allocation and is smaller; stack memory is for dynamic allocation and is slower.

• Stack memory is for dynamic allocation and is larger; heap memory is for static allocation and is faster.

What are the common data structures available in C?

• Arrays, linked lists, stacks, queues, trees, hash tables

• Strings, files, objects, enums

• Dictionaries, lists, arrays, classes

• Graphs, matrices, sets, tuples

How do you open and close a file in C?

• Use fopen() to open a file and fclose() to close it.

• Use read() to open a file and write() to close it.

• Use open() to open a file and close() to close it.

• Call openFile() to open a file and closeFile() to close it.

What is dynamic memory allocation and how is it done in C?

• Dynamic memory allocation is done using static arrays.

• Dynamic memory allocation in C is done using functions like malloc(), calloc(), realloc(), and free() to manage memory at runtime.

• Dynamic memory allocation is managed using global variables.

• Memory allocation in C is only possible at compile time.

Describe how to handle errors in C using errno.

• Check the return value of every function without using errno.

• Use the 'error' function to handle errors in C.

• Use the global variable 'errno' to check for errors after function calls in C.

• Ignore errors and continue execution without any checks.

What is the purpose of the 'malloc' function in C?

• To free up memory used by the program.

• To allocate memory for global variables.

• To initialize static memory at compile time.

• To allocate dynamic memory on the heap.

How do you read data from a file in C?

• Use read() to open the file and write data directly.

• Use fopen() to open the file, then read with fscanf() or fgets(), and close with fclose().

• Open the file with open() and read using readlines().

• Use file() to read the entire file at once.

What is a linked list and how is it implemented in C?

• A linked list is a static data structure that cannot grow or shrink.

• A linked list is a collection of variables stored in contiguous memory locations.

• A linked list is a type of array implemented using loops.

• A linked list is a data structure made of nodes, implemented in C using structures and pointers.

Explain the significance of the 'free' function in memory management.

• The 'free' function allocates memory for new variables.

• The 'free' function is used to initialize memory at the start of a program.

• The 'free' function automatically manages memory without user intervention.

• The 'free' function is significant as it deallocates memory, preventing memory leaks and ensuring efficient memory management.