C
is a general-purpose programming language that is extremely popular,
simple and flexible. It is machine-independent, structured programming
language which is used extensively in various applications.
C
was the basics language to write everything from operating systems
(Windows and many others) to complex programs like the Oracle database,
Git, Python interpreter and more.
It is said that 'C' is a god's
programming language. One can say, C is a base for the programming. If
you know 'C,' you can easily grasp the knowledge of the other
programming languages that uses the concept of 'C'
It
is essential to have a background in computer memory mechanisms because
it is an important aspect when dealing with the C programming language.
The
base or father of programming languages is 'ALGOL.' It was first
introduced in 1960. 'ALGOL' was used on a large basis in European
countries. 'ALGOL' introduced the concept of structured programming to
the developer community. In 1967, a new computer programming language
was announced called as 'BCPL' which stands for Basic Combined
Programming Language. BCPL was designed and developed by Martin
Richards, especially for writing system software. This was the era of
programming languages. Just after three years, in 1970 a new programming
language called 'B' was introduced by Ken Thompson that contained
multiple features of 'BCPL.' This programming language was created using
UNIX operating system at AT&T and Bell Laboratories. Both the
'BCPL' and 'B' were system programming languages.
In
1972, a great computer scientist Dennis Ritchie created a new
programming language called 'C' at the Bell Laboratories. It was created
from 'ALGOL', 'BCPL' and 'B' programming languages. 'C' programming
language contains all the features of these languages and many more
additional concepts that make it unique from other languages.
'C'
is a powerful programming language which is strongly associated with
the UNIX operating system. Even most of the UNIX operating system is
coded in 'C'. Initially 'C' programming was limited to the UNIX
operating system, but as it started spreading around the world, it
became commercial, and many compilers were released for cross-platform
systems. Today 'C' runs under a variety of operating systems and
hardware platforms. As it started evolving many different versions of
the language were released. At times it became difficult for the
developers to keep up with the latest version as the systems were
running under the older versions. To assure that 'C' language will
remain standard, American National Standards Institute (ANSI) defined a
commercial standard for 'C' language in 1989. Later, it was approved by
the International Standards Organization (ISO) in 1990. 'C' programming
language is also called as 'ANSI C'.
Languages
such as C++/Java are developed from 'C'. These languages are widely
used in various technologies. Thus, 'C' forms a base for many other
languages that are currently in use.
As
we studied earlier, 'C' is a base language for many programming
languages. So, learning 'C' as the main language will play an important
role while studying other programming languages. It shares the same
concepts such as data types, operators, control statements and many
more. 'C' can be used widely in various applications. It is a simple
language and provides faster execution. There are many jobs available
for a 'C' developer in the current market.
'C'
is a structured programming language in which program is divided into
various modules. Each module can be written separately and together it
forms a single 'C' program. This structure makes it easy for testing,
maintaining and debugging processes.
'C' contains 32 keywords, various data types and a set of powerful built-in functions that make programming very efficient.
Another
feature of 'C' programming is that it can extend itself. A 'C' program
contains various functions which are part of a library. We can add our
features and functions to the library. We can access and use these
functions anytime we want in our program. This feature makes it simple
while working with complex programming.
Various compilers are available in the market that can be used for executing programs written in this language.
It
is a highly portable language which means programs written in 'C'
language can run on other machines. This feature is essential if we wish
to use or execute the code on another computer.
C
is a compiled language. A compiler is a special tool that compiles the
program and converts it into the object file which is machine readable.
After the compilation process, the linker will combine different object
files and creates a single executable file to run the program. The
following diagram shows the execution of a 'C' program
Nowadays,
various compilers are available online, and you can use any of those
compilers. The functionality will never differ and most of the compilers
will provide the features required to execute both 'C' and 'C++'
programs.
In this tutorial, we will learn to install C in Windows, Mac, and Linux.
Install C on Windows
We will use an open-source Integrated Development environment named
Code::Blocks which bundles a
compiler (named
gcc offered by Free Software Foundation GNU),
editor and
debugger in a neat package.
Step 1) Go to
http://www.codeblocks.org/downloads and click Binary Release.
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Step 2) Choose
the installer with GCC Compiler, e.g., codeblocks-17.12mingw-setup.exe
which includes MinGW's GNU GCC compiler and GNU GDB debugger with
Code::Blocks source files.
Step 3) Run the
downloaded installer and accept the default options.
Step 4) Accept the Agreement
Step 5) Keep the component selection default and click Next.
Step 6) You may change the installation folder and click Next.
Step 7) To launch Code::Blocks double click on the icon.
Step 8) It will detect the gcc compiler automatically, set it as default.
Associate C/C++ files with code::blocks
Step 9) You will see the IDE Home screen.
Install C in Linux
Linux
operating systems mostly comes with GCC preinstalled. To verify if the
compiler is installed on the machine, run the following command in the
terminal:
gcc --version
After executing this command if the gcc is installed on the
machine then it will return the information about the compiler otherwise
it will ask you to install the compiler.
To set up the 'C' environment on Linux distributions follow the given steps:
1. Open terminal.
2. For red-hat, Fedora users, type and execute this command
# yum groupinstall 'Development Tools'
3. For Debian and Ubuntu users, type and execute following command
$ sudo apt-get update
$ sudo apt-get install build-essential manpages-dev
4. To verify that the GCC has been successfully installed on the machine as we discussed earlier, execute the following command
gcc --version
Install C on MAC
To set up a 'C' programming environment on MAC operating system, follow the given steps:
1. Visit the given link
https://developer.apple.com/downloads/index.action and download. You will need an Apple developer ID
"Command Line Tools for X-Code," pick any version (latest version is always recommended) and download the
.dmg file.
2.
After the file is being downloaded on the machine, double click and
follow the wizard and install the file. Always keep the default settings
as suggested by the installation wizard.
3. After the installation process, open a terminal and run gcc -v command to check if everything is successfully installed.
Conclusion:
'C'
program can be written and executed on any machine that has a suitable
environment to run the program. Its recommended using an IDE to run C
programs. An IDE includes a compiler, editor and debugger. Clanfg, MinGW
compiler (Minimalist GNU for Windows), Portable 'C' compiler, Turbo C
are popular compilers available.
Here,
is a Hello World program in C
#include<stdio.h> //Pre-processor directive
void main() //main function declaration
{
printf("Hello World"); //to output the string on a display
getch (); //terminating function
}
Here is the code explanation:
Pre-processor directive
#include is a pre-processor directive in 'C.'
#include <stdio.h>, stdio is the library where the function
printf is defined
. printf
is
used for generating output. Before using this function, we have to
first include the required file, also known as a header file (.h).
You
can also create your own functions, group them in header files and
declare them at the top of the program to use them. To include a file in
a program, use pre-processor directive
#include <file-name>.h
File-name
is the name of a file in which the functions are stored. Pre-processor
directives are always placed at the beginning of the program.
The main function
The main function is a part of every 'C' program. We can represent the main function in various forms, such as:
- main()
- int main()
- void main()
- main(void)
- void main(void)
- int main(void)
The
empty parentheses indicate that this function does not take any
argument, value or a parameter. You can also represent this explicitly
by placing the keyword void inside the parentheses. The keyword void
means the function does not return any value, in this case, the last
statement is always getch ().
#include<stdio.h> //Pre-processor directive
int main() //main function declaration
{
printf("Hello World"); //to output the string on a display
return 0; //terminating function
}
In the above example, the keyword int means the function will
return an integer value. In this case, the last statement should always
return 0.
The source code
After the main function has been declared, we have to specify the opening and closing parentheses.
Curly brackets { },
indicate the starting and end of a program. These brackets must be
always put after the main function. All the program code is written
inside these brackets, such as declarative and executable part.
The
printf function generates the output by passing the text "Hello World!"
The
semicolon ; determines the end of the statement. In C, each statement must end with a semicolon.
So
we have successfully installed the compiler and now can begin working
in 'C.' We will write a simple program that will say hello to us. Let's
start.
How to run C Program
Step 1) Create a new Project
Step 2) In the pop-up,
- Select File
- Choose the "C/C++ Source"
- Click "Go."
Step 3) Continue, by clicking on "Next."
Step 4) To create the new file ,select a "C" file then click on "Next" button to continue.
Step 5) Set the file path by clicking the "..." button, the explorer window permits to create the C file.
Step 6) Select the path of your new C File then its name which has .c extension and save it.
Step 7) Finally, to confirm the C file creation click "Finish."
Step 8) Enter the code, save it and compile it by clicking on the "Build & Run "button.
Here is the result:
Hello, World!
Summary
- The main function is a mandatory part of every 'C' program.
- To use the functionality of a header file, we have to include the file at the beginning of our program.
- Every 'C' program follows a basic structure.
What Is Comment In C Language?
A
comment is an explanation or description of the source code of the
program. It helps a developer explain logic of the code and improves
program readability. At run-time, a comment is ignored by the compiler.
There are two types of comments in C:
1)
A comment that starts with a slash asterisk /* and finishes with an
asterisk slash */ and you can place it anywhere in your code, on the
same line or several lines.
2) Single-line Comments which uses a double slash // dedicated to comment single lines
Example Single Line Comment
// single line comment example
Here is an example of comments type
// C program to demo
// Single Line comment
#include <stdio.h>
int main(void)
{
// This is a single line comment
printf("Guru99");
return 0; // return zero
}
Example Multi Line Comment
/* Sample Multiline Comment
Line 1
Line 2
….
…
*/
Example Single Line Comment
#include <stdio.h>
int main() {
/* in main function
I can write my principal code
And this in several comments line /*
int x = 42; //x is a integer variable
printf("%d", x);
return 0;}
Why do you need comments?
A good programmer
who writes codes understood by a human is better than a programmer who
generates codes understood only by the machine.
So, it is highly
recommended to insert comments to your code because it is good
programming practice. Comments do not affect a program because the
compiler ignores them.
Comments help the developer understand the logic/algorithm of the code if he revisits it after a long time.
Step 3) Run the downloaded installer and accept the default options. 
Step 5) Keep the component selection default and click Next. 
Step 8) It will detect the gcc compiler automatically, set it as default. 
Step 5) Set the file path by clicking the "..." button, the explorer window permits to create the C file. 
Comments