C Interview Questions

C is a general-purpose, procedural programming language developed in the early 1970s for system/software development.

It is known for efficiency, low-level memory manipulation capabilities, and widespread use in operating systems, embedded systems, and device drivers.

C lacks built-in garbage collection and automatic memory management, giving programmers direct control over memory allocation and deallocation.

Its simplicity, portability, and speed continue to make it relevant in areas where performance and resource optimization are paramount.

Pointers in C are variables that store the memory address of another variable, allowing direct manipulation of memory locations.

They are crucial for dynamic memory allocation, array handling, function arguments passed by reference, and efficient data structure implementations like linked lists and trees.

Pointer arithmetic enables navigation through arrays and memory blocks, offering performance benefits in low-level programming.

Improper use of pointers can lead to segmentation faults, memory leaks, and undefined behavior, requiring careful management and understanding of memory concepts.

Mastery of pointers is essential for advanced C programming and system-level development.

Both malloc() and calloc() are used for dynamic memory allocation in C, but they differ in initialization and usage.

malloc() allocates a single block of memory and returns a pointer to the first byte, but it does not initialize the allocated memory, leaving it with garbage values.

calloc() allocates multiple blocks of memory, initializes all bytes to zero, and returns a pointer to the allocated space.

calloc() takes two arguments: number of elements and size of each element, whereas malloc() takes a single argument for total size.

Memory allocated with either function must be explicitly freed using free() to avoid memory leaks.