Pointer Fundamentals and Dynamic Memory Allocation Quiz

Pointers

• Pointer fundamentals: a pointer is a variable that stores the memory address of another variable
• Declaring pointer variables: uses an asterisk (*) symbol, e.g. int *ptr
• Referencing and de-referencing: & operator gets the memory address of a variable, * operator gets the value stored at a memory address
• Pointer arithmetic: allows performing operations on the memory address stored in a pointer

Pointers with Arrays and Strings

• Using pointers with arrays: an array name is a pointer to the first element of the array
• Using pointers with strings: a string is a character array, and a string literal is a pointer to the first character of the string

Array of Pointers and Pointers as Function Arguments

• Array of pointers: an array that stores memory addresses of other variables
• Pointers as function arguments: allows functions to modify the original variables passed as arguments
• Functions returning pointers: a function can return a memory address, which can be used to access the returned value

Dynamic Memory Allocation

• malloc() function: allocates memory of a specified size and returns a pointer to the starting address
• calloc() function: allocates memory for an array and initializes it to zero
• realloc() function: resizes the memory block allocated by malloc() or calloc()
• free() function: releases the memory allocated by malloc(), calloc(), or realloc()
• sizeof operator: returns the size of a variable or data type

Structures

• Declaring a structure: defines a new data type that can store multiple values of different data types
• Reading and assigning structure variables: uses dot notation, e.g. struct_name.member_name
• Array of structures: an array that stores multiple structures
• Arrays within structures: a structure can have an array as a member
• Structures within structures: a structure can have another structure as a member

Comparison with Python

• C structures are similar to Python tuples, but C structures can have members of different data types

Unions

• Defining and working with unions: similar to structures, but all members share the same memory space

File Handling

• Types of files: text files and binary files
• File operations: fopen(), fclose(), fgetc(), fputc(), fgets(), fputs(), fscanf(), fprintf(), getw(), putw(), fread(), fwrite(), fseek()
• fopen() function: opens a file and returns a file pointer
• fclose() function: closes a file
• fgetc() and fputc() functions: read and write a single character from/to a file
• fgets() and fputs() functions: read and write a string from/to a file
• fscanf() and fprintf() functions: read and write formatted data from/to a file
• getw() and putw() functions: read and write a word (integer) from/to a file
• fread() and fwrite() functions: read and write a block of data from/to a file
• fseek() function: moves the file pointer to a specified position in the file

Test your knowledge on pointer variables, referencing, de-referencing, pointer arithmetic, using pointers with arrays and strings, and dynamic memory allocation in C. Explore topics like structure declaration, arrays of structures, and pointers as function arguments.