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Semester 1: Programming in C
Introduction to C Language: Syntax, compilation, identifiers
Introduction to C Language
Syntax
C language syntax consists of rules that define the combinations of symbols that are considered to be correctly structured programs. It includes the use of keywords, operators, and punctuation to form statements. C is a free-form language, meaning that statements can be written in any line and can extend across multiple lines. It requires each statement to end with a semicolon.
Compilation
Compilation in C is the process of converting the source code written in C into executable machine code. The process involves several stages, including preprocessing, compiling, assembling, and linking. The C compiler reads the source code, applies necessary preprocessing directives, translates it into assembly language, and then converts it into machine code.
Identifiers
Identifiers in C are names given to elements of the program such as variables, functions, arrays, etc. They are used to identify these elements uniquely. An identifier can consist of letters, digits, and underscores, but it must begin with a letter or underscore. Identifiers are case-sensitive and should not be any of the reserved keywords in C.
Control Structures: Selection, loops, boolean expressions
Control Structures: Selection, loops, boolean expressions
Selection Structures
Selection structures, also known as conditional statements, allow the execution of different code segments based on specific conditions. Common examples include the if, else if, and else statements, as well as switch-case statements. In C, the if statement evaluates a boolean expression and executes its block if true. The switch-case structure evaluates a variable against multiple potential constant values.
Loops
Loops are control structures that repeat a block of code a certain number of times or until a condition is met. The primary types of loops in C are for, while, and do-while loops. The for loop is typically used when the number of iterations is known, while the while and do-while loops are used when the number of iterations is not known at the outset.
Boolean Expressions
Boolean expressions are fundamental to control structures. They evaluate to true or false, guiding the flow of program execution. In C, boolean expressions can result from relational operators (like <, >, ==) and logical operators (like &&, ||, !). These expressions are often used in condition statements and loop conditions.
Functions: Definition, calling, recursion
Functions in Programming
Definition of Functions
A function is a block of code designed to perform a specific task. Functions are used to encapsulate code for reusability and to manage complexity in programming.
Calling Functions
To execute a function, you need to call it by its name followed by parentheses. You can pass arguments to the function inside the parentheses, which the function can use as input.
Return Values
Functions can return a value after performing computations. The `return` statement is used for this purpose. If no return type is specified, the function returns a default value.
Types of Functions
Functions can be categorized into built-in functions, user-defined functions, and library functions. User-defined functions are created by programmers to meet specific needs.
Recursion
Recursion is a programming technique where a function calls itself to solve smaller subproblems. A recursive function must have a base case to terminate the recursive calls.
Importance of Functions
Functions help in reducing code redundancy, enhancing readability, and making debugging easier. They promote modular code and enable easier maintenance.
Objects, modular programming
Objects and Modular Programming in C
Introduction to Objects in C
C does not support objects natively as it is a procedural programming language. However, structures can be used to create objects. A structure is a user-defined data type that groups related variables.
Defining Structures
A structure is defined using the 'struct' keyword followed by the structure name and its members. Example: struct Student { int id; char name[50]; };.
Using Structures as Objects
Structures can be used to create objects by defining functions that operate on these structures. This simulates object-oriented behavior.
Modular Programming Defined
Modular programming is a software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules.
Benefits of Modular Programming
Modular programming promotes code reusability, improves maintainability, and allows for easier debugging. It also facilitates collaborative development.
Functions and Header Files
In C, functions are the basic units of modular programming. Header files can be used to declare functions and structures, providing a clear interface between different modules.
Implementation of Modular Programs
A modular program can consist of multiple source files. Each module can be compiled separately which makes it easier to manage large code bases.
Example of Modular Programming in C
An example project might include multiple files such as main.c, student.c, and student.h. This structure allows for organized code and easier navigation.
Best Practices in Modular Programming
Key practices include naming conventions, keeping modules focused on a single task, and ensuring good documentation for each module.
File handling and exception management
File handling and exception management in C
Introduction to File Handling
File handling in C involves the use of file pointers and standard I/O functions to read from and write to files. Basic operations include opening, reading, writing, and closing files.
File Types and Modes
C supports different types of files such as text and binary files. File modes include read, write, append, and their variations that can be used to manipulate files as required.
File Operations
Key file operations include fopen() to open a file, fclose() to close it, fread() and fwrite() for reading and writing data, and fprintf() and fscanf() for formatted input/output.
Error Handling in File Operations
Error handling when dealing with files is important. Functions like ferror() can be used to check for errors and handle them gracefully.
Introduction to Exception Management
Exception management in C is not as native as in some other languages, but error checking mechanisms can be implemented using return values and specific error handling logic.
Using errno for Error Reporting
The errno variable is used to report errors such as file not found or permission denied. It provides an additional way to determine the type of error occurred.
Best Practices in File Handling
Best practices include checking return values of file operations, properly closing files, and using functions like clearerr() to reset the error indicators.
