Question: ```
#define IS_THIS_CORRECT(X) if(X){}

```

I have this preprocessor statement defined in my project. I am trying to understand how to use this function.

Answer: 
```
#define IS_THIS_CORRECT(X) if(X){}

```

It can be used to check if `X` (any value) is not zero or is not an empty string etc. You can do the following

```
IS_THIS_CORRECT("Hello")
else puts("The string is empty");

```

You'd better surround `X` with another pair of braces for more safety:

```
#define IS_THIS_CORRECT(X) if((X)){}

```

I suggest you to rename this preprocessor statement as `IT_IS_CORRECT` or even `IS_CORRECT` for more readability.
As this is currently written, there is very little possible *meaningful* use of it, except you want to handle only FALSE cases based on the value of `X`.

IMHO, you can re-write it as

```
#define IS_THIS_CORRECT(X) if(X)

```

then, you can use it like

```
 int p = 5;
 IS_THIS_CORRECT(X)
 {
      printf("yay !!!\n");
 }

```