C Programming: Functions and Directives

C Functions

• Declaration: Defines the function's return type, name, and parameters.
• Definition: Contains the actual code that the function executes.
• Scope: Refers to the accessibility of a function within a program.
• Recursion: A function calling itself to solve a problem.
• Call by value: Passes a copy of the argument to the function.
• Call by reference: Passes the address of the argument to the function.

Preprocessor Directives

• #define: Defines a macro, which can be a constant or a code snippet.
• Macros with arguments: Allows for flexible substitution based on provided inputs.
• Nested Macros: Macros can be defined within other macros.
• # and ## operators: Used for string concatenation and token pasting within macros.

Storage Classes

• Automatic: Variables declared within a function, exist only during the function's execution.
• External (global): Variables declared outside any function, accessible from anywhere in the program.
• Static: Variables retain their value across function calls, they are not accessible from outside their scope.
• Register: Variables are stored in the processor's registers for faster access.

Arrays

• 1D Arrays: Linear data structure storing elements of the same data type.
• 2D Arrays: Multi-dimensional data structure representing a grid of elements.
• Strings: Arrays of characters representing textual data.

Pointers

• Basic Pointers: Variables that store memory addresses of other variables.
• Pointer Arithmetic: Mathematical operations involving pointers to navigate memory locations.
• Pointer to Pointer: Pointer variables that store the address of another pointer.
• Array & Pointer Relationship: Arrays can be treated as pointers, they store the address of the first element.
• Array of Pointers: Arrays containing pointers to different data locations.
• Pointers to functions: Pointers that hold the address of a function, enabling function calls through pointers.
• Returning Pointers: Functions can return pointers to dynamically allocated memory or other data structures.

Dynamic Memory Allocation

• Provides the ability to allocate memory during runtime as needed.
• Allows for flexible data structures and efficient resource management.

This quiz covers key concepts of C programming, focusing on functions, preprocessor directives, and storage classes. Test your knowledge on function declarations, definitions, recursion, and macro usage. Enhance your understanding of how these elements work within the C programming environment.