Keywords are the words in a program that offer specific instructions to the Java compiler. These words cannot be used as variable names because their presence in your Java program have very distinct meanings and can be thought of as placeholders for specific Java functionality.
The Java keywords are
abstract
boolean
break
byte
case
catch
char
class
const
continue
default
do
double
else
extends
false
final
finally
float
for
goto
if
implements
import
instanceof
int
interface
long
native
new
null
package
private
protected
public
return
short
static
super
switch
synchronized
this
throw
throws
transient
true
try
void
volatile
while
Each of these keywords will be discussed in detail as you read through this and the following chapters. For now pay particular attention so that you don't use any of these words as names for your variables.