PROGRAMMING IN C UNIT 1 (INTRODUCTION TO C ) (BTPS101-18), Study notes of C programming

Download PROGRAMMING IN C UNIT 1 (INTRODUCTION TO C ) (BTPS101-18) and more Study notes C programming in PDF only on Docsity!

· Programming for Problem Solving

· Unit-1: Introduction to Programming

· Themed & Designed Summary

· Date: June 27, 2025

· Programming for Problem Solving

· Unit-1: Introduction to Programming

"Programming for Problem Solving” -Unit-1 Introduction to Programming

● Introduction to Computer System: ○ A computer is an electronic device made of hardware and software. 1

○ It takes input (data), processes it, stores intermediate and final data, and provides output (information). 2

○ A diagram illustrates the flow: Input -> Processor (CPU - Arithmetic Logic Unit, Control Unit) -> Storage Unit (Primary, Secondary) -> Output (Information). 3

○ Computer Hardware: Refers to the physical components like CPU and mouse that perform physical work. 4

○ Computer Software: Commands hardware on what and how to do tasks. 5

○ Components of Computer System (Major Tasks): Input, Process (calculations/operations), Control (transformation process), Storage (intermediate and final results), Provides Output (information). 6

○ Types of Software: System Software (e.g., Windows, Unix) and Application Software (e.g., MS Office programs, games, Paint, MS Word). ● Characteristics of Computer: ○ Speed: Dependent on CPU speed, calculated by instructions performed per second, measured in Hertz (Hz). 7

○ Accuracy/Correctness: Performs tasks accurately. Garbage Input leads to Garbage Output. 8

○ Automation: Once input is given, the computer automatically processes it to provide desired output. 9

○ Diligence: Computers don't get tired of repetitive tasks, performing them with the same accuracy and execution time. 10

○ Performs tasks with the same efficiency even if many are assigned. 11

○ Memory: Stores final and intermediate results. 12

● Operating System:

○ The primary goal is to make computer systems convenient and efficient. 13

○ Ensures efficient use of system resources like memory and I/O devices. 14

○ Important for an OS to have a control policy and algorithm to manage system resources, especially with multiple programs residing in memory. 15

○ Examples: Windows, Linux, Unix. 16

● Introduction to C Language: ○ A high-level programming language given by Dennis Ritchie in 1972 at Bell Labs, California, USA. 17

○ Popular because it is simple and easy to use. 18

○ Enables programmers to concentrate on problem-solving, not machine code. 19

○ Small in size, has 32 keywords. 20

○ Structured language: code can be organized using functions. 21

○ Makes efficient use of function calls. 22

○ Supports pointers, arrays, structures, unions. 23

○ A core language for many other programming languages like C++, Java. 24

● Steps in Learning C Language: ○ Similar to learning English (Alphabets -> Words -> Sentences -> Paragraphs). ○ C language elements: Digits (0-9), Alphabets (A-Z, a-z), Special Symbols (+, -, *, @, $, etc.). 25

○ Character Sets: Include digits (0-9), capital (A-Z) and small (a-z) characters. ○ Tokens: Basic building blocks in C, the smallest individual unit in a C program. (^26) Programs are constructed using combinations of tokens. 27 Examples:

int, a, ;, sum are all tokens. 28

○ Constants: Numerical digits that remain unchanged. 29 Cannot be null. 30 Can be single characters or strings.

○ Operators: Used to perform specific arithmetic operations or tasks (+, -, *, /). ○ Keywords: Reserved or predefined words with fixed meanings. C has 32 keywords (e.g., if, else, case). ○ Instructions: Set of commands given to the compiler. A program is a set of instructions. ○ Identifier: Helps identify data (variables, arrays, functions). Can consist of letters, numerals, or underscores. 31 Examples:

int sum = a + b;, int roll_no;. ● Types of Instructions in C Language: ○ Type Declaration Instruction: Declares the type of variable (e.g., int a = 0, 1, -1). 32

○ Arithmetic Instruction: Performs arithmetic operations, contains operators and operands (values on which operations are performed). 33 Example:

a = b + c;. 34

○ Control Instruction: Controls the execution sequence of statements (e.g., conditional statements, looping statements). 35

● Errors in Programming (Bugs): ○ Errors are problems or faults that make a program behave abnormally. ○ The process of removing bugs is "Debugging." 36

○ Errors are found by the compiler. 37

○ Types of Errors:^38

■ Syntax Error (Compile-time errors): Occur when rules of C programming are broken (e.g., missing semicolon). 39

■ Run-Time Error: Occur when the program is running, even after successful compilation. Often due to segmentation faults (programs trying to access unauthorized memory). 40 Example: Accessing

a[10] in an array declared as int array[5]. 41 This leads to abnormal behavior or garbage values. 42

■ Logical Error: Occur when syntax is correct, but the desired result is not achieved due to logical issues. 43 Example:

• ○ #include<conio.h>: Console input/output header file.
• ○ Format Specifiers: %d (integer), %c (character), %f (float), %s (string).
• ○ &: Address operator.