Keywords In Java Programming Language

Keywords In Java Programming Language: Keywords in Java programming are reserved words that are fundamental building blocks for writing code. These words have predefined meanings and cannot be used for other purposes, such as naming variables or functions.

Java has a specific set of keywords integral to the language’s syntax and semantics. Understanding these keywords is essential for any Java programmer, as they dictate the structure and behavior of Java programs.

This blog post will discuss the most commonly used Java keywords and their roles in shaping the language’s functionality.

What are Keywords In Java Programming?

In Java, keywords are reserved words with predefined meanings integral to the language’s syntax. They cannot be used as identifiers (e.g., variable names, method names, class names) because they have special roles and functionalities within the language.

List Of Keywords Keywords In Java Language

Java has many reserved keywords that serve special purposes in the language. These words, such as “public,” “class,” “static,” and more. These reserve words cannot be used as names for variables, classes, or functions.

It’s crucial to note that Java keywords are case-sensitive, meaning they must be written in lowercase. While you can technically change one or more letters to uppercase to use them as identifiers, this is discouraged and considered bad practice.

Two keywords, “const” and “goto,” are reserved in Java but not actively used. Additionally, Java reserves “true,” “false,” and “null” as values with specific meanings. These words cannot be utilized as names for your variables, classes, or other identifiers.

You don’t need to memorize all the Java keywords right away; you’ll encounter and learn about them in different chapters as you progress in your Java programming journey.

Keywords for Class – Building – Handling – Managing Tools

abstractUsed to declare abstract classes and methods.
extendsSpecifies inheritance in class declarations.
implementsSpecifies that a class implements one or more interfaces.
importUsed to import classes and packages from other Java files.
packageUsed to define a package that contains classes.

Keywords: For Exception Handling

tryDefines a block of code that may generate exceptions.
throwUsed to throw an exception.
catchUsed in exception handling to catch and handle exceptions.
assertUsed in assertion statements to test assumptions about program behavior.
finallyUsed in exception handling to specify a block of code that is always executed.

Keywords For Object Reference

superRefers to the superclass (parent class) of an object.
thisRefers to the current object instance.

Reserved Keywords In Java For Future

strictfpRefers to the superclass (parent class) of an object.
constIt was used to declare constants, but it’s not recommended in modern Java; use final instead.

Modifier Keywords in Java

finalUsed to declare a constant, make a class not inheritable, or make a method not overrideable.
privateSpecifies that a class member (field or method) is accessible only within its own class.
protectedSpecifies that a class member is accessible within its own class and subclasses.
publicSpecifies that a class member is accessible from any other class.
synchronizedEnsures that only one thread can access a synchronized block or method simultaneously.
volatileEnsures that only one thread can access a synchronized block or method simultaneously.
transientSpecifies that a field should not be serialized when an object is written to persistent storage.
nativeUsed in conjunction with if to specify an alternative condition.
staticSpecifies that multiple threads may modify a field.

Flow Control Keywords in Java

whileUsed to create a while loop.
doUsed to create a do-while loop.
forUsed to create a for loop.
breakUsed to exit from loops and switch statements.
continueUsed to continue to the next iteration of a loop.
switchUsed to create a switch statement.
caseUsed in a switch statement to specify different cases.
defaultSpecifies a default case in a switch statement.
ifUsed to create conditional statements.
elseUsed in conjunction with if to specify an alternative condition.
returnUsed to exit a method and return a value.

Keyword Operators In The Sense That They Could Well Be Functions

instanceofUsed to test if an object is an instance of a particular class or interface.
newUsed to create new objects.

Data And Data Types Keywords in Java

booleanRepresents a boolean data type with values true or false.
byteRepresents a byte data type, typically used for small integers.
charRepresents a character data type enclosed in single quotes (e.g., ‘A’ ).
shortRepresents a short integer data type.
intRepresents an integer data type.
longRepresents a long integer data type.
classUsed to declare a class.
enumUsed to declare an enumeration.
interfaceUsed to declare an interface.
floatRepresents a single-precision floating-point data type.
doubleRepresents a double-precision floating-point data type.
voidIndicates that a method does not return a value.
nullrepresents a null reference
TRUEboolean literal
FALSEboolean literal

Please note that Java may introduce new keywords in later versions, and the usage and significance of keywords can evolve over time. It’s essential to consult the documentation for the specific version of Java you are using to ensure accurate keyword usage.


Keywords in the Java programming language are reserved words with predefined meanings and are fundamental elements for writing code. These keywords cannot be used for any other purpose, such as naming variables or functions, and must be written in lowercase due to Java’s case sensitivity.

Understanding and correctly using keywords is essential for writing valid and functional Java programs. While there are many keywords in Java, it’s unnecessary to memorize them all at once; you will become familiar with them as you explore different aspects of Java programming.

Overall, keywords are the building blocks that shape the structure and behavior of Java programs, making them a fundamental concept for any Java programmer to grasp.

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