JAVA-Keywords - Notes By ShariqSP
Keywords in Java
Keywords in Java are reserved words that have predefined meanings and cannot be used as identifiers (such as variable names, class names, etc.). They play a crucial role in defining the syntax and structure of Java programs.
Keywords are used to define the control flow, data types, modifiers, and other aspects of Java programs. They provide specific functionalities and operations within the language.
Keyword | Description |
---|---|
abstract |
Used to declare abstract classes and methods, which are incomplete and must be implemented by subclasses. |
assert |
Enables assertion checking to test assumptions about the program's behavior. |
boolean |
Defines a data type that can store either true or false values. |
break |
Used to terminate a loop or switch statement prematurely. |
byte |
Defines a data type that can store integer values from -128 to 127. |
case |
Specifies a branch in a switch statement. |
catch |
Handles exceptions thrown by try blocks. |
char |
Defines a data type that can store single characters. |
class |
Declares a class. |
const |
Reserved for future use, not currently used. |
continue |
Skips the rest of the current loop iteration and continues to the next iteration. |
default |
Specifies the default case in a switch statement. |
do |
Starts a do-while loop. |
double |
Defines a data type that can store double-precision floating-point numbers. |
else |
Specifies an alternative branch in an if-else statement. |
enum |
Declares an enumeration (a special type of class with a fixed set of constants). |
extends |
Indicates that a class inherits from another class (implements inheritance). |
final |
Indicates that a variable, method, or class cannot be modified or extended. |
finally |
Defines a block of code that will be executed after a try-catch block, regardless of whether an exception occurred or not. |
float |
Defines a data type that can store single-precision floating-point numbers. |
for |
Starts a for loop. |
goto |
Reserved for future use, not currently used. |
if |
Specifies a conditional statement. |
implements |
Indicates that a class implements an interface. |
import |
Imports packages or classes into the current source file. |
instanceof |
Checks whether an object is an instance of a specific class or interface. |
int |
Defines a data type that can store integer values. |
interface |
Declares an interface (a collection of abstract methods and constants). |
long |
Defines a data type that can store integer values with a wider range. |
native |
Indicates that a method is implemented in native code using a language other than Java. |
new |
Creates new objects. |
package |
Declares a package, which is a namespace that organizes a set of related classes and interfaces. |
private |
Specifies that an element (variable, method, or class) is accessible only within its own class. |
protected |
Specifies that an element is accessible within its own package and by subclasses. |
public |
Specifies that an element is accessible from any other class. |
return |
Returns a value from a method. |
short |
Defines a data type that can store integer values with a smaller range. |
static |
Indicates that a variable, method, or block belongs to the class rather than any specific instance of the class. |
strictfp |
Ensures consistent floating-point calculations across different platforms. |
super |
Refers to the superclass of the current object. |
switch |
Specifies a multi-way branch statement. |
synchronized |
Controls access to shared resources in a multithreaded environment. |
this |
Refers to the current object. |
throw |
Throws an exception. |
throws |
Indicates that a method may throw certain types of exceptions. |
transient |
Specifies that a variable should not be serialized. |
try |
Starts a block of code that will be tested for exceptions. |
void |
Specifies that a method does not return a value. |
volatile |
Indicates that a variable may be modified asynchronously. |
while |
Starts a while loop. |