I am creating a program to convert from binary, decimal, hex, and oct to any one of those options. For hex, I need a way to format values greater than 9 into one of A, B, C, D, E, F. Since this will be repeated in several functions, I decided to make the following function:

```
char hexRepresentation(double n){
    if(n > 9){
        if(n==10) return 'A';
        if(n==11) return 'B';
        if(n==12) return 'C';
        if(n==13) return 'D';
        if(n==14) return 'E';
        if(n==15) return 'F';
    }

    return (char)n;
}

```

However, when I try to compile, I receive the error

> 
> conflicting types for 'hexRepresentation'
> 
> 
> 

I'm utterly new at C, coming from Java, and am banging my head against a wall over what should be the simplest things to implement. Any help would be greatly appreciated!