C program Syntax

To start with the C Programming Language journey, let’s compile and execute a simple C program and understand its syntax line by line.

C Hello World Program

Below is a C program that prints “Hello World!” to the console:

#include <stdio.h>
// Hello World program
int main()
printf("Hello World!");
return 0;

C program Syntax Explained

Line1: #include is the header file library; it includes a “standard input-output” Library. printf() function is available in stdio.h Library.

Line2: // is a single-line comment, and the compiler consistently ignores multi or single-line comments. We add the comments to increase the understanding of the reader. It will not affect program functionality and will also not get displayed on the screen.

Line3: int main() is the main entry point of every C program. C program starts from the main() function.

Line4: { is the opening curly brackets. Every function contains the opening and closing curly brackets {} after the function name, which means C executes any function code between the curly brackets {}. Remember, you are writing opening curly brackets {, and you must have to close it by giving closing brackets }.

Line5: printf() function displays the data like the “Hello World” on the screen. The Semicolon ; ends the C statement.

Line6: return 0; ends the main() function by returning the implementation status to the OS. The 0 value returns successful execution, and value 1 returns unsuccessful execution.

In the next lesson, you will learn in detail about printf() function and other important Output Functions in C.