C Programming Fundamentals

Data Types

Primitive Data Types in C:

• int: integer, whole numbers (e.g., 1, 2, 3, etc.)
• float: floating-point numbers (e.g., 3.14, -0.5, etc.)
• char: single character (e.g., 'a', 'A', '0', etc.)
• double: double precision floating-point numbers (e.g., 3.14159, -0.0005, etc.)
• void: no value, used for functions that don't return a value

Derived Data Types in C:

• array: a collection of values of the same type (e.g., int scores[5];)
• pointer: a variable that holds a memory address (e.g., int *ptr;)
• structure: a collection of values of different types (e.g., struct Person { int age; char name[20]; };)

Computer Architecture

Basic Components:

• CPU (Central Processing Unit): executes instructions
• Memory: stores data and program instructions
• Input/Output Devices: keyboards, monitors, printers, etc.

Memory Hierarchy:

• Registers: small, fast memory inside the CPU
• Cache Memory: small, fast memory between registers and main memory
• Main Memory: larger, slower memory for data and program instructions
• Secondary Storage: slow, non-volatile memory for data storage (e.g., hard drives, SSDs)

Functions in C

Function Definition:

• A block of code that performs a specific task
• Consists of a function name, return type, and parameters (if any)

Function Types:

• Library Functions: pre-written functions in the C standard library (e.g., printf(), scanf())
• User-Defined Functions: created by the programmer to perform specific tasks

Function Calling:

• Function Call: when a function is invoked in the program
• Function Arguments: values passed to a function when it's called
• Function Return: value returned by a function to the calling program