abstract |
Specifies that a class or method will be implemented later, in a subclass |
assert |
Assert describes a predicate placed in a Java program to indicate that the developer thinks that the predicate is always true at that place. |
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 8-bit 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 16-bit 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 do-while loop |
double |
A data type that can hold 64-bit floating-point numbers |
else |
Indicates alternative branches in an if statement |
enum |
A Java keyword is 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 try-catch structure that will always be executed |
float |
A data type that holds a 32-bit floating-point 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 32-bit signed integer |
interface |
Declares an interface |
long |
A data type that holds a 64-bit integer |
native |
Specifies that a method is implemented with native (platform-specific) code |
new |
Creates new objects |
null |
This 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 16-bit integer |
static |
Indicates that a variable or method is a class method (rather than being limited to one particular object) |
strictfp |
A Java keyword is 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 |
This indicates that a variable may change asynchronously |
while |
Starts a while loop |