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# C Program without main() function - Programming Puzzles
- URL: https://developerinsider.co/c-program-without-main-function-programming-puzzles/
- Published: 2016-10-16T17:11:00.000Z
- Updated: 2018-03-29T17:01:15.000Z
- Author: Vineet Choudhary
- Tags: Programming Puzzles, Puzzles

We can write c program without using main() function. To do so, we need to use #define preprocessor directive.

The C preprocessor is a micro processor that is used by compiler to transform your code before compilation. It is called micro preprocessor because it allows us to add macros.

A macro is a segment of code which is replaced by the value of macro. Macro is defined by #define directive.

For example:

```c
#define PI 3.14

```

Here, PI is the macro name which will be replaced by the value 3.14.

Let's see a simple program to print "Hello, World!!!" without main() function.

```c
#include<stdio.h>  
#define start main  
void start() 
{  
   printf("Hello, World!!!");  
}  

```

Output:

```
Hello, World!!!

```