Introduction
Now that you have set up your development environment, it’s time to write and run your first C program. In this chapter, we will take a look into the steps to create a simple “Hello, World!” program, compile it, and run it.
Steps to Write and Run Your First C Program
1. Create a New File
- Open Your IDE or Text Editor:
- Launch the IDE or text editor you installed earlier (e.g., Visual Studio Code, Code::Blocks, Eclipse).
- Create a New File:
- Create a new file and save it with a
.c
extension. For example, name ithello.c
.
- Create a new file and save it with a
2. Write the Code
- Type the Following Code into Your New File:
#include <stdio.h>
int main() {
printf("Hello, World!\n");
return 0;
}
- Explanation:
#include <stdio.h>
: This line tells the compiler to include the standard input/output library, which is necessary for using theprintf
function.int main()
: This defines the main function, which is the entry point of every C program.printf("Hello, World!\n");
: This line prints the text “Hello, World!” to the console.return 0;
: This line ends the main function and returns 0 to the operating system, indicating that the program ran successfully.
3. Save the File
- Save Your Code:
- Make sure you save the file after writing your code.
4. Compile the Program
- Open a Terminal or Command Prompt:
- Navigate to the directory where your
hello.c
file is saved.
- Navigate to the directory where your
- Compile the Code:
- Type the following command to compile your program:
- GCC:
gcc hello.c -o hello
- Clang:
clang hello.c -o hello
- Visual Studio (Developer Command Prompt):
cl hello.c
- GCC:
- Type the following command to compile your program:
- Explanation:
gcc hello.c -o hello
: This command tells the GCC compiler to compilehello.c
and output an executable namedhello
.clang hello.c -o hello
: This command tells the Clang compiler to compilehello.c
and output an executable namedhello
.cl hello.c
: This command tells the Visual Studio compiler to compilehello.c
.
5. Run the Program
- Run the Executable:
- After compiling, run the program by typing the following command in the terminal or command prompt:
- Linux/macOS:
./hello
- Windows:
hello
- Linux/macOS:
- After compiling, run the program by typing the following command in the terminal or command prompt:
- Expected Output:
- You should see the text “Hello, World!” printed on the screen.
6. Verify the Output
- Check the Output:
- If you see “Hello, World!” on your screen, congratulations! You have successfully written, compiled, and run your first C program.
Conclusion
Writing and running your first C program is a significant milestone in learning C programming. By following these steps, you have created a simple program, compiled it using a C compiler, and executed it to see the output. This process forms the foundation of working with C, and you can now move on to writing more complex programs.