“Char cannot be dereferenced” error

Question

I'm trying to use the char method isLetter(), which is supposed to return boolean value corresponding to whether the character is a letter. But when I call the method, I get an error stating that "char cannot be dereferenced." I don't know what it means to dereference a char or how to fix the error. the statement in question is:

if (ch.isLetter()) 
{
....
....
}

Any help? What does it mean to dereference a char and how do I avoid doing so?

Answer 1

The type char is a primitive -- not an object -- so it cannot be dereferenced

Dereferencing is the process of accessing the value referred to by a reference. Since a char is already a value (not a reference), it can not be dereferenced.

use Character class:

if(Character.isLetter(c)) {

Answer 2

I guess ch is a declared as char. Since char is a primitive data type and not and object, you can't call any methof from it. You should use Character.isLetter(ch).

Answer 3

A char doesn't have any methods - it's a Java primitive. You're looking for the Character wrapper class.

The usage would be:

if(Character.isLetter(ch)) { //... }

Answer 4

If Character.isLetter(ch) looks a bit wordy/ugly you can use a static import.

import static java.lang.Character.*;


if(isLetter(ch)) {

} else if(isDigit(ch)) {

}