List of Java Keywords

Keyword	Description
abstract	Specifies that a class or method will be implemented later, in a subclass
assert	Assert describes a predicate (a true–false statement) placed in a Java program to indicate that the developer thinks that the predicate is always true at that place. If an assertion evaluates to false at runtime, an assertion failure results, which typically causes execution to abort.
boolean	A data type that can hold True and False values only
break	A control statement for breaking out of loops
byte	A data type that can hold 8bit data values
case	Used in switch statements to mark blocks of text
catch	Catches exceptions generated by try statements
char	A data type that can hold unsigned 16bit Unicode characters
class	Declares a new class
continue	Sends control back outside a loop
default	Specifies the default block of code in a switch statement
do	Starts a dowhile loop
double	A data type that can hold 64bit floatingpoint numbers
else	Indicates alternative branches in an if statement
enum	A Java keyword used to declare an enumerated type. Enumerations extend the base class
extends	Indicates that a class is derived from another class or interface
final	Indicates that a variable holds a constant value or that a method will not be overridden
finally	Indicates a block of code in a trycatch structure that will always be executed
float	A data type that holds a 32bit floatingpoint number
for	Used to start a for loop
if	Tests a true/false expression and branches accordingly
implements	Specifies that a class implements an interface
import	References other classes
instanceof	Indicates whether an object is an instance of a specific class or implements an interface
int	A data type that can hold a 32bit signed integer
interface	Declares an interface
long	A data type that holds a 64bit integer
native	Specifies that a method is implemented with native (platformspecific) code
new	Creates new objects
null	Indicates that a reference does not refer to anything
package	Declares a Java package
private	An access specifier indicating that a method or variable may be accessed only in the class it’s declared in
protected	An access specifier indicating that a method or variable may only be accessed in the class it’s declared in (or a subclass of the
class	it’s declared in or other classes in the same package)
public	An access specifier used for classes, interfaces, methods, and variables indicating that an item is accessible throughout the application (or where the class that defines it is accessible)
return	Sends control and possibly a return value back from a called method
short	A data type that can hold a 16bit integer
static	Indicates that a variable or method is a class method (rather than being limited to one particular object)
strictfp	A Java keyword used to restrict the precision and rounding of floating point calculations to ensure portability
super	Refers to a class’s base class (used in a method or class constructor)
switch	A statement that executes code based on a test value
synchronized	Specifies critical sections or methods in multithreaded code
this	Refers to the current object in a method or constructor
throw	Creates an exception
throws	Indicates what exceptions may be thrown by a method
transient	Specifies that a variable is not part of an object’s persistent state
try	Starts a block of code that will be tested for exceptions
void	Specifies that a method does not have a return value
volatile	Indicates that a variable may change asynchronously
while	Starts a while loop