What is C Language? A Complete Guide for Beginners

The C Programming Language is a procedural, imperative, and general-purpose language utilized for coding applications that can run across multiple platforms. C is a compiled language that undergoes a conversion process into machine-level code, which can then be executed by the computer. As a low-level programming language, C offers direct access to the memory and hardware resources of the computer, thereby enabling developers to create code that is both fast and efficient.

Watch the video below to learn the fundamentals of C

What is C Language?

C is considered a structured programming language that supports both low-level and high-level programming, making it adaptable for both system and application-level programming. It is also recognized as a middle-level language that combines the attributes of both assembly-level and high-level languages. This article will provide an overview, in simple terms, of the C programming language, its structure, data types, features, keywords, operators, variables, and applications.

Features of C 

The C programming language possesses numerous features that make it a prime option for creating system-level software applications. Below are some of its notable features of C language:

• Modularity – Modularity is a key feature of C that enables developers to write code in small, reusable modules. This makes it simpler to maintain and debug the code.
  
• Efficiency – C is a programming language that is highly esteemed for its remarkable efficiency. It is capable of running at a low level and granting developers an unparalleled level of control over system resources. This exceptional degree of control is made possible through its profound comprehension of the underlying hardware, enabling it to optimize and streamline operations with exquisite precision. As a result, C language is widely acknowledged as a high-performance language that serves as an indispensable tool for programmers striving to maximize their efficiency and control over intricate systems.
• Portability – The programming language C provides developers with the ability to write code that operates at a low level, which grants them greater influence over the hardware that the code is running on.
• Modularity – C is endowed with the capability to accommodate modular programming techniques, which ultimately allows for intricate programs to be dissected into smaller, more manageable functions or modules. This programming paradigm is particularly advantageous as it facilitates improved code readability, fosters code reuse, and encourages code maintainability.
• Rich Library Support – C, the programming language, has a large library of pre-existing functions that can be used to help create robust software.
• Memory Management – C provides direct access to memory through pointers, enabling efficient manipulation and allocation of memory.

Structure in C Language

C programs follow a specific structure that consists of several components. Below is a typical structure in the C language

• Preprocessor Directives – Preprocessor instructions within the C language are important commands that the preprocessor processes prior to the actual compilation of the program. These directives are indicated by the hash symbol (#) and are typically utilized to import header files or establish immutable values or macros that will be exploited across the entire program. These preprocessing instructions are run before the code is compiled, and their purpose is to prepare the code for compilation by the compiler.
• Global Declarations – Global declaration in C refers to the act of defining a variable or function at the highest level of the program, thereby endowing it with accessibility from any part of the program. If no initial value is supplied, global variables are automatically initialized to zero or NULL. Correspondingly, global functions have the capability of being utilized across diverse parts of the program. However, excessive use of global variables or functions has the potential to cause problems with program maintenance and should therefore be used with caution.

• Main Function – The primary routine in C is where the program begins execution in a way that leaves no doubt. This routine is responsible for collecting user input and providing the user with output.
  
• Function Definitions – A function definition in C includes the instructions that are executed when the function is called, along with essential details regarding the name, parameter(s), and return type of the function. In contrast to other programming languages, C’s function definition bears specific indications regarding the return type, function name, and input parameters.

Data Types in C

C facilitates a wide range of data types that can be employed to declare variables. The data types in C can be categorized into four classes: primary data types, acquired data types, enumeration data types, and null data types. Here are the data types supported by C.

• Basic Data Types – Fundamental data classifications in C include integers (integers), floating point numerical quantities (float), characters (char), and boolean data types (bool). These data types are responsible for encapsulating true or false values. The goal is to store diverse categories of values and perform logical and mathematical computations on them.
  
• Derived Data Types –  Derived data types within C refer to data types that originate from fundamental data types. These derived data types, namely arrays, structures, and pointers, enable the construction of complex data structures capable of storing numerous items of diverse types.
  
• Enumeration Data Types – Enumeration data types, an essential concept in C, allow you to create a new data type with predetermined and specific values. These values are conventionally denoted using symbols or tokens, thereby facilitating better comprehension and readability of the program’s code.

• Void Data Types – There is a unique data type known as “void” in the field of C, which represents the noticeable lack of any particular value.” This particular type is most typically used as a return type for functions that do not return any value.

Operators in C Language

Operators are symbols that perform specific operations on operands (variables or values). operators in C are categorized into the following types

• Arithmetic Operators – Arithmetic operators, which are symbols utilized in C, serve the purpose of performing mathematical operations on numerical values. These operators consist of the addition operator (+), the subtraction operator (-), the multiplication operator (*), the division operator (/), and the modulus operator (%).
  
• Relational Operators – Relational operators in the programming language C are utilized as symbols to carry out the comparison of two values or expressions. This comparison produces a boolean value, which is either true or false. These relational operators include the equal to operator (==), not equal to operator (!=), less than operator (<), less than or equal to operator (<=), greater than operator (>), and greater than or equal to operator (>=).
  
• Logical Operators – Logical operators in C are utilized to merge or alter conditions within logical expressions. The three most widely employed logical operators in C  are the double ampersand symbol (&&), representing the logical “AND” operator, the double vertical line symbol (||), which signifies the logical “OR” operator, and the exclamation mark (!), which denotes the logical “NOT” operator.
  
• Bitwise Operators – Bitwise operators in the programming language C are utilized to execute operations at the bit level on integer data types. These operators allow you to manipulate individual bits of a variable by setting, clearing, or toggling them. Common bitwise operators in the language C encompass AND (&), OR (|), XOR (^), left shift (<<), and right shift (>>).
  
• Assignment Operators – In C, the assignment operator denoted by the symbol “=” is employed to ascribe a particular value to a variable. To elaborate, in case there exists a variable named “x” and we intend to set its value to 5, we can articulate the assignment statement as “x = 5”.
  
• Unary Operators – A unary operator denotes an operator that performs an operation on a single operand, exclusively. Its primary function is to carry out various actions such as the increment or decrement of a variable, the negation of an expression, or the determination of the magnitude of a data type.
  
• Ternary Operator – The ternary operator in C provides an easy way to create an if-else statement. This operator employs three operands: a condition to be evaluated, an expression to be returned if the condition is true, and an expression to be returned if the condition is false. The syntax for the ternary operator is as follows:
  condition?  expression_if_true : expression_if_false

For instance

x > y ? printf("x is greater") : printf("y is greater");

This particular statement examines whether x is greater than y. If this condition holds true, then it outputs “x is greater”. On the other hand, if the condition evaluates to false, it prints “y is greater”.

Variables in C

A variable represents a designated area within a computer’s memory that contains a value of a distinct data type. This entity is given the name “variable”, as the value it holds is not set in stone and may be altered during program execution.

Variables in C are a key part of programming since they allow us to store and manipulate data in our programmatic efforts. To use a variable in C, we must first declare it with a specific data type and then give it a specific name. We can then assign a value to said variable and, alternatively, change said value later in the program’s execution.

Keywords in C Language

In C, keywords are reserved words with special meanings that cannot be used as identifiers (variable or function names). The following are some of the most common keywords in C

• int, float, double, char, void: These are used to define data types.
• if, else, switch, case, default: These are used for conditional statements.
• for, while, do: These are used for loop control structures.
• break, continue: These are used to alter the flow of loops.
• return: This is used to return a value from a function.
• struct, union: These are used to define complex data structures.
• typedef: This is used to create new data type names.
• const, volatile: These are used as type qualifiers.

Applications of C Language

C has been a versatile tool for developing a wide range of software applications. Operating systems such as Linux, Unix, and Windows are prominent examples of systems written in C. Furthermore, C has found applications in the construction of embedded systems such as microcontrollers. Microcontrollers are used in a wide range of applications, from medical gadgets to home appliances and automobiles.

Furthermore, the importance of C extends beyond operating and embedded systems. C has also benefited the gaming industry since it enables low-level access to computer hardware, which is essential for designing high-performance games. C is also used to construct database systems such as MySQL, PostgreSQL, and SQLite, where it has been shown to be a valuable tool.

The importance of C is particularly noticeable in the field of web development. C is essential in the development of web servers such as Apache Hadoop and Nginx, which provide web pages to users and act as the internet’s basics. Furthermore, C is important in the design of compilers, which are computer programs that convert source code into machine code.

Moreover, C is widely used in scientific computing due to its capability to process large data sets efficiently and quickly. With its versatility, C is a powerful asset in scientific computing.

The C programming language is a durable and flexible programming language that has a wide range of applications. Whether it’s operating systems, video games, embedded systems, or scientific computers, the C language’s importance in the programming world is undeniable.

Conclusion

The C programming language has stood the test of time because of its toughness and adaptability. Its efficacy and adaptability make it an excellent choice for a wide range of applications, from operating systems to embedded devices. Learning the properties, configuration, data categories, operators, and variables of C will help you grasp this vital programming language.