Reference - Java Keyword
Java reserved keywords
abstract
A non-access modifier.
Used for classes and methods
-
An abstract class cannot be used to create objects (to access it, it must be inherited from another class)
-
An abstract method can only be used in an abstract class(it does not have a body, the body is provided by the subclass)
assert
For debugging
boolean
A data type that can only store true and false values
break
breaks out of a loop or a switch block
byte
A data type that can store whole numbers from –128 and 127
case
Marks a block of code in switch statements
catch
Catches exceptions generated by try statements
char
A data type that is used to store a single character
class
Defines a class
continue
Continues to the next iteration of a loop
default
Specifies the default block of code in a switch statement
do
Used together with while to create a do-while loop
double
A data type that can store whole numbers from 1.7e-308 to 1.7e+308
else
Used in conditional statements
enum
Declares an enumerated(unchangeable) type
exports
Exports a package with a module
extends
Extends a class(indicates that a class is inherited from another class)
final
A non-access modifier, makes non-changeable(impossible to inherit or override)
finally
Used with exceptions, a block of code that will be executed no matter if there is an exception or not
float
A data type that can store whole numbers form 3.4e-038 to 3.4e+038
for
Create a for loop
if
Makes a conditional statement
implements
Implements an interface
import
Used to import a package, class or interface
instanceof
Check whether an object is an instance of a specific class or an interface
int
A data type that can store whole numbers from –2147483648 to 2147483647
interface
Used to declare a special type of class that only contains abstract methods
long
A data type that can store whole numbers from –9223372036854775808 to 9223372036854775808
module
Declares a module
native
Specifies that a method is not implemented in the same Java source file(but in another language)
new
Creates new objects
package
Declares a package
private
An access modifier, making accessible within the declared class(so class can’t use)
protected
An access modifier, making accessible in the same package and subclasses(so class can’t use)
public
An access modifier, making accessible by any other class
requires
Specifies required libraries inside a module
return
Finished the execution of a method, and can be used to return a value from a method
short
A data type that can store whole numbers from –32768 to 32767
static
A non-access modifier used for method and attributes
It can be accessed without creating an object of a class
strictfp
Restrict the precision and rounding of floating point calculations
super
Refers to superclass(parent) objects
switch
Selects one of many code blocks to be executed
synchronized
A non-access modifier, which specifies that methods can only be accessed by one thread at a time
this
Refers to the current object in a method or constructor
throw
Creates a custom error
throws
Indicates what exceptions may be thrown by a method
transient
A non-access modifier, which specifies that an attribute is not part of an object’s persistent state
try
Creates a try…catch statement
var
Declares a variable
void
Specifies that a method should not have a return value
volatile
Indicates that an attribute is not cached thread-locally
Is always read from the “main memory”
while
Creates a while loop