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.
1 2 3 4 5 6 | #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 thestdio.h
library that provides standard input/output functions. We used theprintf()
function, which is declared in thestdio.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 ofmain()
function to its end. - Third, you notice that we used the
printf()
function that accepts a string as a parameter. Theprintf()
function is used to display a string on the screen. Themain()
function is supposed to return an integer so we put thereturn 0
statement at the end of the program. You can omit thereturn
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…
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!