"Hello World!" First Program In C Language

Summary: in this tutorial, you will learn step-by-step how to develop the first simple but famous program called C Hello World.

A C program consists of functions. A C program always starts executing in a special function called main() function. The following is the C Hello World program that displays a greeting message on the screen.

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#include <stdio.h> main() {     printf("Hello World!\n");     return 0; }

Let’s examine the program in more detail.

• First, we have the #include directive. Every directive in C is denoted by a hash ( #) sign. C program uses this directive to load external function library. In the program, we used the stdio.hlibrary that provides standard input/output functions.  We used the printf() function, which is declared in the stdio.h header file, to display a message on the screen.
• Next, you see the main() function. The main() function is the entry point of  every C program. A C program logic starts from the beginning of main() function to its end.
• Third, you notice that we used the printf() function that accepts a string as a parameter. The printf() function is used to display a string on the screen. The main() function is supposed to return an integer so we put the return 0 statement at the end of the program. You can omit the return statement, which is fine.

Developing C Hello World program in CodeBlocks IDE

In the following section, we will show you step-by-step running the C Hello World using CodeBlock IDE. If you don’t have any C IDE installed in your system, you can setup CodeBlocks IDEB by following the setting up C development environment tutorial.

Launch the IDE, and create a project from the menu File > New > Project…

Choose Console application

Choose C language

Enter project name and folder to create project

Click Run button you will see the console window display the Hello world! message

Congratulation! You have been successfully developing and running the first C Hello World program. Let’s go to the next tutorial to explore the power of C programming language. Enjoy programming with C!