C programs with output showing usage of operators, loops, functions, arrays, performing operations on strings, files, pointers. Download executable files and execute them without compiling the source file. Code::Blocks IDE is used to write programs, most of these will work with GCC and Dev C++ compilers. The first program, prints 'Hello World.'
C programming examples with output
Example 1 - C hello world program
/** My first C program */
May 08, 2014 In the past week or so, I have been getting a warning box that shows up on my desk top (of Windows 8) whenever I boot up. It says 'There is a file or folder called 'c: Program' which could cause certain applications to not function correctly. Renaming it to 'c: Program1' would solve this problem. Would you like to rename it now?'
int main()
{
printf('Hello Worldn');
return0;
}
Output of program:
'Hello World'
Example 2 - C program to get input from a user using scanf
#include <stdio.h>int main()
{
int x;
printf('Input an integern');
scanf('%d',&x);// %d is used for an integer
printf('The integer is: %dn', x);
return0;
}
Output:
Input an integer
7897
The integer is: 7897
Example 3 - using if else control instructions
#include <stdio.h>int main()
{
int n;
printf('Enter a numbern');
scanf('%d',&n);
if(n >0)
printf('Greater than zero.n');
else
printf('Less than or equal to zero.n');
return0;
}
Output:
Enter a number
-45
Less than or equal to zero.
Example 4 - while loop example
int main()
{
int c =1;// Initializing variable
while(c <=10)// While loop will execute till the condition is true
{
printf('%d ', c);// Note the space after %d for gap in the numbers we want in output
c++;
}
return0;
}
Output:
1 2 3 4 5 6 7 8 9 10
Example 5 - C program check if an integer is prime or not
C Programs In Dev C 2018
int main()
{
int n, c;
printf('Enter a numbern');
scanf('%d',&n);
if(n 2)
printf('Prime number.n');
else
{
for(c =2; c <= n -1; c++)
{
if(n % c 0)
break;
}
if(c != n)
printf('Not prime.n');
else
printf('Prime number.n');
}
return0;
}
Example 6 - command line arguments
#include <stdio.h>int main(int argc,char*argv[])
{
int c;
printf('Number of command line arguments passed: %dn', argc);
for(c =0; c < argc; c++)
printf('%d argument is %sn', c +1, argv[c]);
return0;
}
This program prints the number of arguments and their contents.
Example 7 - Array program
#include <stdio.h>int main()
{
int array[100], n, c;
printf('Enter number of elements in arrayn');
scanf('%d',&n);
printf('Enter %d elementsn', n);
for(c =0; c < n; c++)
scanf('%d',&array[c]);
printf('The array elements are:n');
for(c =0; c < n; c++)
printf('%dn', array[c]);
return0;
}
Example 8 - function program
#include <stdio.h>void my_function();// Declaring a function
int main()
{
printf('Main function.n');
my_function();// Calling the function
printf('Back in function main.n');
return0;
}
// Defining the function
void my_function()
{
printf('Welcome to my function. Feel at home.n');
}
Example 9 - Using comments in a program
int main()
{
// Single line comment in a C program
printf('Writing comments is very useful.n');
/*
* Multi-line comment syntax
* Comments help us to understand a program later easily.
* Will you write comments while writing programs?
*/
printf('Good luck C programmer.n');
return0;
}
Example 10 - using structures in C programming
#include <stdio.h>#include <string.h>
struct game
{
char game_name[50];
int number_of_players;
};// Note the semicolon
int main()
{
struct game g;
strcpy(g.game_name,'Cricket');
g.number_of_players=11;
printf('Name of game: %sn', g.game_name);
printf('Number of players: %dn', g.number_of_players);
return0;
}
Example 11 - C program for Fibonacci series
#include <stdio.h>int main()
{
int n, first =0, second =1, next, c;
printf('Enter the number of termsn');
scanf('%d',&n);
printf('First %d terms of Fibonacci series are:n', n);
for(c =0; c < n; c++)
{
if(c <=1)
next = c;
else
{
next = first + second;
first = second;
second = next;
}
printf('%dn', next);
}
return0;
}
Example 12 - C graphics programming
#include <graphics.h>#include <conio.h>
int main()
{
int gd = DETECT, gm;
initgraph(&gd,&gm,'C:TCBGI');
outtextxy(10,20,'Graphics programming is fun!');
circle(200,200,50);
setcolor(BLUE);
line(350,250,450,50);
getch();
closegraph();
return0;
}
How to compile C programs with GCC compiler?
If you are using GCC on Linux operating system, then you may need to modify the programs. For example, consider the following program that prints the first ten natural numbers.
#include <stdio.h>#include <conio.h>
int main()
{
int c;
for(c =1; c <=10; c++)
printf('%dn', c);
getch();
return0;
}
The program includes a header file <conio.h>
and uses function getch, but this file is Borland specific, so it works in Turbo C compiler but not in GCC. The program for GCC must be like:
int main()
{
int c;
/* for loop */
for(c =1; c <=10; c++)
printf('%dn', c);
return0;
}
If you are using GCC, save the program in a file say 'numbers.c' to compile the program, open the terminal and enter the command 'gcc numbers.c', this compile the program and to execute it enter the command './a.out' do not use quotes while executing commands. You can specify the output file name as 'gcc numbers.c -o numbers.out', to run execute './numbers.out' in the terminal.
C programming tutorial
A program consists of functions that contain instructions given to a machine to perform a task. The process of writing it includes designing an algorithm, drawing a flowchart, and then writing code. After writing it, you need to test it and debug it if it does not produce the required output.
To write a program, you need a text editor (use your favorite one) and a compiler. A compiler converts source code into machine code, which consists of zero's and one's only, ready to be executed on a machine.
An IDE (Integrated Development Environment) provides a text editor, compiler, debugger, etc. for developing programs and managing projects. Code::Blocks IDE provides an ideal environment for development. It can import Microsoft Visual C++ projects, is extendable as it uses plug-ins, open-source, and cross-platform.
C Programs In Dev C Download
How to write a C program?
A program must have at least one function which must be main. A function consists of declarations and statements. A statement is an expression followed by a semicolon. For example, a + b, printf('C program examples') are expressions and a + b; and printf('C is an easy to learn computer programming language'); are statements.
To use a variable, we must indicate its type, whether it is an integer, float, character, or others. C language has many built-in data types, and we can create our own using structures and unions. Every data type has its size that may depend on the machine; for example, an integer may be of 2 or 4 Bytes. Data is stored in a binary form, i.e., a group of bits where each bit can be '0' or '1'.
Keywords such as 'switch,' 'case,' 'default,' 'register,' are reserved words with predefined meaning and can't be used as the name of a variable or a function. Memory can be allocated at compile-time or run-time using malloc and calloc functions. C language has many features such as recursion, preprocessor, conditional compilation, portability, pointers, multi-threading by using external libraries, dynamic memory allocation. Thanks to these, it is used for making portable software programs and applications. Using networking API's users can communicate and interact with each other and share files.
C standard library contains functions for mathematical operations, characters, input/output, files, and many more. The process of making a program which is known as coding requires knowledge of programming language and logic to achieve the desired output. So you should learn C programming basics and start making programs.
Learning data structures (stacks, queues, linked lists) using C provides you a greater understanding as you learn everything in detail. A general belief is to go for high-level languages. However, it's a good idea to learn C before learning C++ or Java. C++ is object-oriented and contains all features of C, so learning C help you learn C++ quickly, then you can study Java.
C programming PDF
C programming books
- Let Us C By Yashavant Kanetkar
- PROGRAMMING WITH C By Byron Gottfried, Jitender Chhabra
- The C Programming By Brian Kernighan and Dennis Ritchie
If you are a beginner, buy any one of the first two books, and if you have previous programming experience or you know the basics of C language, buy the third one.
-->Visual C++ includes a C compiler that you can use to create everything from basic console programs to full Windows Desktop applications, mobile apps, and more.
This walkthrough shows how to create a basic, 'Hello, World'-style C program by using a text editor, and then compile it on the command line. If you'd rather work in C++ on the command line, see Walkthrough: Compiling a Native C++ Program on the Command Line. If you'd like to try the Visual Studio IDE instead of using the command line, see Walkthrough: Working with Projects and Solutions (C++) or Using the Visual Studio IDE for C++ Desktop Development.
Prerequisites
To complete this walkthrough, you must have installed either Visual Studio and the optional Visual C++ components, or the Build Tools for Visual Studio.
Visual Studio is a powerful integrated development environment that supports a full-featured editor, resource managers, debuggers, and compilers for many languages and platforms. For information on these features and how to download and install Visual Studio, including the free Visual Studio Community edition, see Install Visual Studio.
The Build Tools for Visual Studio version of Visual Studio installs only the command-line toolset, the compilers, tools, and libraries you need to build C and C++ programs. It's perfect for build labs or classroom exercises and installs relatively quickly. To install only the command-line toolset, download Build Tools for Visual Studio from the Visual Studio downloads page and run the installer. In the Visual Studio installer, select the C++ build tools workload, and choose Install.
Before you can build a C or C++ program on the command line, you must verify that the tools are installed, and that you can access them from the command line. Visual C++ has complex requirements for the command-line environment to find the tools, headers, and libraries it uses. You can't use Visual C++ in a plain command prompt window without some preparation. You need a developer command prompt window, which is a regular command prompt window that has all the required environment variables set. Fortunately, Visual C++ installs shortcuts for you to launch developer command prompts that have the environment set up for command line builds. Unfortunately, the names of the developer command prompt shortcuts and where they're located are different in almost every version of Visual C++ and on different versions of Windows. Your first walkthrough task is to find the right shortcut to use.
Dev C++ Programming Manual
Note
A developer command prompt shortcut automatically sets the correct paths for the compiler and tools, and for any required headers and libraries. Some of these values are different for each build configuration. You must set these environment values yourself if you don't use one of the shortcuts. For more information, see Set the Path and Environment Variables for Command-Line Builds. Because the build environment is complex, we strongly recommend you use a developer command prompt shortcut instead of building your own.
These instructions vary depending on which version of Visual Studio you are using. To see the documentation for your preferred version of Visual Studio, use the Version selector control. It's found at the top of the table of contents on this page.
Open a developer command prompt in Visual Studio 2019
If you have installed Visual Studio 2019 on Windows 10, open the Start menu, and then scroll down and open the Visual Studio 2019 folder (not the Visual Studio 2019 app). Choose Developer Command Prompt for VS 2019 to open the command prompt window.
C Program In Dev C++
If you're using a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.
Open a developer command prompt in Visual Studio 2017
If you have installed Visual Studio 2017 on Windows 10, open the Start menu, and then scroll down and open the Visual Studio 2017 folder (not the Visual Studio 2017 app). Choose Developer Command Prompt for VS 2017 to open the command prompt window.
If you're running a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.
Open a developer command prompt in Visual Studio 2015
If you have installed Microsoft Visual C++ Build Tools 2015 on Windows 10, open the Start menu, and then scroll down and open the Visual C++ Build Tools folder. Choose Visual C++ 2015 x86 Native Tools Command Prompt to open the command prompt window.
If you're running a different version of Windows, look in your Start menu or Start page for a Visual Studio tools folder that contains a developer command prompt shortcut. You can also use the Windows search function to search for 'developer command prompt' and choose one that matches your installed version of Visual Studio. Use the shortcut to open the command prompt window.
Next, verify that the Visual C++ developer command prompt is set up correctly. In the command prompt window, enter cl
and verify that the output looks something like this:
There may be differences in the current directory or version numbers, depending on the version of Visual C++ and any updates installed. If the above output is similar to what you see, then you're ready to build C or C++ programs at the command line.
Note
If you get an error such as 'cl' is not recognized as an internal or external command, operable program or batch file,' error C1034, or error LNK1104 when you run the cl command, then either you are not using a developer command prompt, or something is wrong with your installation of Visual C++. You must fix this issue before you can continue.
If you can't find the developer command prompt shortcut, or if you get an error message when you enter cl
, then your Visual C++ installation may have a problem. If you're using Visual Studio 2017 or later, try reinstalling the Desktop development with C++ workload in the Visual Studio installer. For details, see Install C++ support in Visual Studio. Or, reinstall the Build Tools from the Visual Studio downloads page. Don't go on to the next section until this works. For more information about installing and troubleshooting Visual Studio, see Install Visual Studio.
How To Save C Program In Dev C++
Note
Depending on the version of Windows on the computer and the system security configuration, you might have to right-click to open the shortcut menu for the developer command prompt shortcut and then choose Run as Administrator to successfully build and run the program that you create by following this walkthrough.
Create a C source file and compile it on the command line
In the developer command prompt window, enter
cd c:
to change the current working directory to the root of your C: drive. Next, entermd c:simple
to create a directory, and then entercd c:simple
to change to that directory. This directory will hold your source file and the compiled program.Enter
notepad simple.c
at the developer command prompt. In the Notepad alert dialog that pops up, choose Yes to create a new simple.c file in your working directory.In Notepad, enter the following lines of code:
On the Notepad menu bar, choose File > Save to save simple.c in your working directory.
Switch back to the developer command prompt window. Enter
dir
at the command prompt to list the contents of the c:simple directory. You should see the source file simple.c in the directory listing, which looks something like:The dates and other details will differ on your computer. If you don't see your source code file, simple.c, make sure you've changed to the c:simple directory you created, and in Notepad, make sure that you saved your source file in this directory. Also make sure that you saved the source code with a .c file name extension, not a .txt extension.
To compile your program, enter
cl simple.c
at the developer command prompt.You can see the executable program name, simple.exe, in the lines of output information that the compiler displays:
Note
If you get an error such as 'cl' is not recognized as an internal or external command, operable program or batch file,' error C1034, or error LNK1104, your developer command prompt is not set up correctly. For information on how to fix this issue, go back to the Open a developer command prompt section.
Note
If you get a different compiler or linker error or warning, review your source code to correct any errors, then save it and run the compiler again. For information about specific errors, use the search box at the top of this page to look for the error number.
To run your program, enter
simple
at the command prompt.The program displays this text and then exits:
Congratulations, you've compiled and run a C program by using the command line.
Next steps
This 'Hello, World' example is about as simple as a C program can get. Real world programs have header files and more source files, link in libraries, and do useful work.
You can use the steps in this walkthrough to build your own C code instead of typing the sample code shown. You can also build many C code sample programs that you find elsewhere. To compile a program that has additional source code files, enter them all on the command line, like:
cl file1.c file2.c file3.c
The compiler outputs a program called file1.exe. To change the name to program1.exe, add an /out linker option:
cl file1.c file2.c file3.c /link /out:program1.exe
And to catch more programming mistakes automatically, we recommend you compile by using either the /W3 or /W4 warning level option:
cl /W4 file1.c file2.c file3.c /link /out:program1.exe
The compiler, cl.exe, has many more options you can apply to build, optimize, debug, and analyze your code. For a quick list, enter cl /?
at the developer command prompt. You can also compile and link separately and apply linker options in more complex build scenarios. For more information on compiler and linker options and usage, see C/C++ Building Reference.
You can use NMAKE and makefiles, or MSBuild and project files to configure and build more complex projects on the command line. For more information on using these tools, see NMAKE Reference and MSBuild.
The C and C++ languages are similar, but not the same. The Microsoft C/C++ compiler (MSVC) uses a simple rule to determine which language to use when it compiles your code. By default, the MSVC compiler treats all files that end in .c as C source code, and all files that end in .cpp as C++ source code. To force the compiler to treat all files as C non-dependent of file name extension, use the /Tc compiler option.
C And C++ Programs
MSVC is compatible with the ISO C99 standard, but not strictly compliant. In most cases, portable C code will compile and run as expected. Visual C++ doesn't support most of the changes in ISO C11. Certain library functions and POSIX function names are deprecated by MSVC. The functions are supported, but the preferred names have changed. For more information, see Security Features in the CRT and Compiler Warning (level 3) C4996.
See also
How To Debug C Program In Dev C++
Walkthrough: Creating a Standard C++ Program (C++)
C Language Reference
Projects and build systems
Compatibility