New to Java

So, I have no experience with using null, but the code I am working on requires char to be set to null, specifically values in a char array.

According to the book I'm using, "null is a special constant that can be used to give a value to any variable of any class type". However, when I try to set an item in the char array to null, the compiler returns

Error: incompatible types
found : <nulltype>
required: char

So, I'm wondering if this is possible at all. Or how to do it exactly.

Thanks.