Your first C program
You will learn to write a “Hello, World!” program in this section.
Why “Hello, World!” program?
“Hello, World!” is a simple program that displays “Hello, World!” on the screen. Since, it’s a very simple program, it is used to illustrate the basic syntax of any programming language.
This program is often used to introduce programming language to a beginner. So, let’s get started.
#include <stdio.h>int main(){printf("Hello, World!\n");return 0;}
How “Hello, World!” program works?
Include stdio.h header file in your program.
C programming is small and cannot do much by itself. You need to use libraries that are necessary to run the program. The
stdio.h is a header file and C compiler knows the location of that file. To use the file, you need to include it in your program using #includepreprocessor.
Why do you need stdio.h file in this program?
In this program, we have used
printf() function which displays the text inside the quotation mark. Since printf() is defined in stdio.h, you need to include stdio.h.
The main() function
In C programming, the code execution begins from the start of main() function (doesn’t matter if
main() isn’t located at the beginning).
The code inside the curly braces { } is the body of
main() function. The main() function is mandatory in every C program.int main() {
}
This program doesn’t do anything but, it’s a valid C program.
The printf() function
The
printf() is a library function that sends formatted output to the screen (displays the string inside the quotation mark). Notice the semicolon at the end of the statement.
In our program, it displays Hello, World! on the screen.
Remember, you need to include
stdio.h file in your program for this to work.
The return statement
The return statement
return 0; inside the main() function ends the program. This statement isn’t mandatory. However, it’s considered good programming practice to use it