C Programming Language Quiz

Introduction to C Programming

• Welcome to the course
• Instructor: A/Prof Frank Guan, PhD
• Course name: INF1002 – Programming Fundamentals
• Week 8: Introduction to C
• Course themes: Thinking, Able to Learn, Catalysts, and Grounded, as a community, transformative learning
• Research Interests: Virtual Reality (VR), Augmented Reality (AR), Artificial Intelligence (AI), Entrepreneurship & innovation
• Contact Email: [email protected]

Course Housekeeping

• Lectures are online (Zoom)
• Recordings are available
• Focus on the lecture and limit distractions
• Ask questions: voice up or type in the window
• Respectful and honest conduct within the community

Agenda for Week 8

• History of C
• From Python to C
• Simple C program
• Basic data types
• C formatted I/O
• Control structures

Recommended Reading

• Paul Deitel and Harvey Deitel, C: How to Program, 9th Edition (Pearson, 2021)

History of C

• J. Presper Eckert and John Mauchly (1943–1946): Electronic Numerical Integrator and Computer
• Martin Richard (1966–1967): Basic Combined Programming Language
• Ken Thompson (1969, Bell Lab): Developed B, based on BCPL
• Dennis Ritchie (1972–1973, Bell Lab): Created C, rewriting UNIX in C (1973)
• 1970s: Traditional C
• 1989: C89/ANSI C/Standard C
• 1990: ANSI/ISO C
• 1999: C99: attempt to standardize variations

C vs. Related Languages

• More recent derivatives: C++, Objective C, C#
• Influenced by: Java, Perl, Python (quite different)
• C lacks: Exceptions, Range-checking, Garbage collection, Object-oriented programming
• Low-level languages, usually faster code

Compilers vs. Interpreters

• Python uses an interpreter to execute a program
• In C, the compiler converts a program into machine code
• Machine code can be executed directly by the CPU

Variable Declarations

• C requires variable declarations, informing the compiler about the variable before it's used, specifying type.
• Once declared, a variable's type cannot be changed.
• In Python, no declarations are needed.

Whitespace

• Python uses whitespace characters for identifying statements and code blocks
• C uses whitespace only to separate words.

Functions

• All C code is within functions
• The main() function is the starting point for a C program

Good Coding Practices in C

• Indent blocks of code as in Python.
• Format braces and whitespace consistently
• Use comments to explain code for other programmers.
• Use meaningful variable names.
• Pay attention to compiler warnings (indicate syntax correct but potential run-time errors).
• Avoid system-specific features (the code should run on diverse systems without modification).

Simple C Program

• /* ... */ indicates comments (ignored by the compiler)
• #include <stdio.h> includes the standard input/output library
• int main() { ... } defines the main program function
• printf("Hello world!\n"); displays output on the screen
• return 0; signifies successful execution.

C Preprocessor

• Executes before compilation
• Defines symbolic constants
• Includes other files

#define directive

• Creates symbolic constants in C
• Replaces occurrences during compilation.

#include directive

• Includes header files into the program for necessary functions (such as stdio.h for standard input/output)
• Normal usage includes angle brackets <> (standard libraries) or double quotes "" (user-defined files) for specifying location
• Two forms of #include specify standard or user-defined file location.

Header files

• Contain function prototypes (declarations without body):
• Definitions of constants.
• Definitions of various data types.

Variable Declarations in C

• Must specify type before use (int, float, char).
• Variables cannot change type once declared.
• Variables are named integer1, integer2, sum

scanf() Function in C

• Reads formatted input from the standard input (usually the keyboard)

Formatted Input/Output

• printf() formats and displays output to the console
  • Uses format specifiers (e.g., %d, %f, %s) to define the output format.
• scanf() reads input from the console
  • Uses format specifiers for input.
• puts() prints a string and prepends a newline at the end.
• getchar() reads and returns a character from the console as an integer

Escape Sequences

• Used to represent special characters in strings
• Examples include \n (newline), \t (tab), and \" (double quote)

C Control Structures

• if/else for decision-making
• switch for multiple-case decisions
• for and while loops for iteration
• do-while loop

Arrays

• An array is a collection of elements of the same type, stored contiguously in memory.
• Character arrays are used to represent strings.
• Arrays can be declared/initialised, and array elements can be identified using indices, starting with zero.

Structure

• A structure in C is a collection of variables of different types, grouped together under one name.
• Structures can be passed to functions in C

Dynamic Memory Allocation

• Allocates memory at runtime
• Allocates memory for variables that are not known in advance, using malloc() and calloc() .
• malloc(): Allocates a block of memory in heap.
• calloc(): Allocates a block of memory and sets all bytes to zero.

Void Pointers

• Can point to any data type
• Should be cast before dereferencing

Pointers

• Variables that stores memory addresses
• Declaration via int *ptr

Strings

• Array of characters ending in \0

C File Handling

• fopen(): Opens a file.

fprintf()

• Writes formatted data to a file.

fscanf()

• Reads formatted data from a file.

fclose()

• Closes a file.

File Types

• Binary or text

Random Access Files

• Can access any file position.
• Records are of the same length.

Test your knowledge about the C programming language with this comprehensive quiz. Explore its history, features, and key concepts, including important developers and standards. Whether you are a beginner or have some experience, this quiz will challenge your understanding of C.