What is C?
C Programming is a general-purpose language. It is regarded as strong and widely utilized. C is called a middle-level language because it has low-level language traits and is more user- and machine-friendly. It can conduct high-level and low-level operations, like assembly language. Because it can give access to machine-level concepts like bytes and addresses, it is also specifically classified as a low-level language. C is regarded as dependable, straightforward, and user-friendly.
C is a small language with few features. It makes extensive use of a “library” of common functions. C is a permissive language that gives programmers a lot of freedom and thinks they know what they’re doing. Both modular and structured programming are supported. C has a wide range of data types and operators, as well as contemporary data structures and control flow.
The language is renowned for its compactness of code, economy of expression, and simplicity of expression. With no intrinsic limitations that would confine it to a particular field, C is adaptable and has a broad range of applications. It employs a system of static types.
C is UNIX’s native language and was created with writing operating systems in mind. The external function, a type of routine in which arguments are given call-by-value, is supported. Nesting functions is prohibited. The static storage class in files offers a restricted level of anonymity. Prototypes are one of the features in C that were taken from C++. Java and C++ are also said to have their roots in C.
C’s broad range of uses demonstrates its general-purpose character. It is used to create both application and system software, even though it was created for systems programming. Among its uses are:
- Creating operating systems and other system software, such as the UNIX kernel, parts of Windows, and Linux.
- Constructing language-specific compilers.
- Creating application software, including spreadsheets, databases (like Microsoft SQL Server, Oracle, and MySQL), and graphical programs like photo editors (like Adobe Photoshop) and computer and mobile games.
- Assessing equations in mathematics.
- Creating network equipment.
- Creating GUI Applications.
- Regulating various hardware kinds.
Key Concepts in C
The sources emphasise a number of core ideas in C:
Character Set: C Character sets are used while writing programs. White spaces (blank space, new line, carriage return, horizontal tab), digits (0–9), capital and lowercase letters (A–Z), and special characters are all included in this.
Tokens: A sequence of tokens makes up a C program. The fundamental components that the compiler recognises are tokens. They are the program’s smallest individual units. Keywords, constants, strings, operators, identifiers, and special symbols are examples of tokens. Tokens can be separated by punctuation, operators, and white space.
Keywords: Words that are not suitable for use as identifiers because they have unique meanings for the compiler. They have unchangeable, definite meanings. C contains thirty-two keywords. Lowercase letters must be used when writing keywords.
Identifiers: Names assigned to functions, variables, etc. Starting with a letter or underscore, identifier construction rules use letters, numbers, and underscores. Program components are identified by identifiers.
Constants: Data points whose values remain constant while the program runs. Character constants, string constants, integer constants, and floating point constants are examples of types. A constant is a value that remains constant while a program is running. The #define preprocessing directive is used to declare constants.
Variables: Data points whose values are subject to change while the application is running. An identifier used to hold a value is called a variable. Before being used, variables need to be declared with a specified data type. Both local and global variables are possible. Local variables are those that are used within a function.
Data Types: There are many data kinds in C. Data types, such as character, integer, or floating-point, specify the type of data. Int (integer), char (character), float (single-precision floating point), double (double-precision floating point), and void are the primary (basic) types. For integers, qualifiers such as short and long are applicable. For integer types, signed and unsigned apply. The range and size of each data type vary.
Operators and Expressions: Operators are symbols that tell the computer how to manipulate data stored in variables in a mathematical or logical way. Arithmetic (+, -, *, /, %), relational, and logical operators are among the functions that C offers. Operators and operands (variables and constants) are used in an expression to calculate a value. It is implied that the conditional operator? : is a ternary operator. The operators increment (++) and decrement (–) are helpful. The size of an operand in bytes is returned by the sizeof operator.
Statements: Commands that the program carries out. The semicolon ; usually marks the end of a statement in C. By itself, a semicolon is a null assertion. Long C statements should be avoided; they shouldn’t run on forever.
Control Flow Statements: Basic constructs for managing the execution sequence are provided by C. These include looping (while, for, do-while), selection (switch), and decision making (if, if-else, nested if, nested else-if). Break, continue, and goto are examples of jump statements. Break is used to end switch statements or loops. Continue bypasses the loop’s current iteration.
Functions: A function is a group of one or more statements that work together to accomplish a certain goal. Functions are thought of as a collection of building elements that make up C programs. Values can be returned by functions. Usually, arguments are sent by value, which means copies of the parameters are passed to the called function. Only one value can be returned by a function. The return type appears first in function declarations. The main() function is required to begin a C program’s execution.
In order to prevent copying, functions frequently need to be able to change variables in the caller or get a pointer to a huge data object. Through pass-by-reference, this can be accomplished. The return type is always used at the beginning of user-defined functions.
Input/Output: The standard library has I/O facilities. There are standard I/O functions in the header file. Printf() and scanf() are frequently used functions for formatted output and input, respectively. A single character is read by getchar() and shown by putchar(). File I/O is also supported by the standard library using functions like fopen, fclose, getc, putc, fgets, and fputs. For reading in a multi-word string, gets() is a better fit. puts() shows a string with a newline character after it. Using the scanf() function, input is obtained. The function printf() is used to display output.