Java Keywords & Identifiers1 min read


Keywords in Java are also known as reserved words, are already defined in Java with a predefined meaning. These words cannot be used with variables or object name.

Example of using integer Keyword:

List of Keywords used in Java are shown in the table:

abstract assert boolean break
byte case catch char
do double else enum
extends final finally float
for goto if implements
import instanceof int interface
long native new package
short static strictfp super
volatile while this throw
private protected public return
throws transient try void


Identifier is the symbolic name given to the variables name, class name, method name, etc for identification reason so that the program can identify them throughout the program. The name is given by the user with their choice but by following naming rules.

These rules are:

  • An identifier cannot be a Java keyword.
  • Identifiers are case sensitive, that temp and Temp are different identifiers.
  • Identifiers must begin with a sequence of letters(A-Z, a-z) and digits(0-9), $ or _. Note that an identifier cannot have the first letter as a digit.
  • Whitespaces are not allowed.
  • Also symbol like @, #, and so on cannot be used.

Example of some valid identifiers are:

Here are some invalid identifiers:


Java Program to check Krishnamurthy Number

In this tutorial, we will learn about Krishnamurthy numbers and write a Krishnamurthy Number program in Java. We will write two programs for Krishnamurthy number …
Read More

Java Program for ISBN Number

In this tutorial, we will learn about the ISBN (International Standard Book Number) and write a program to check for the ISBN Number in Java …
Read More

C++ Memory Management

Memory management refers to the process of managing the computer memory while assigning the space to the program’s variable to improve the overall performance. Requirement …
Read More

C++ Pointer to Pointer

As we know by now that a pointer stores the address of the pointed variable. But it is not the only use, pointer also stores …
Read More

C++ Passing Pointers to Functions

A function is a user-defined block of codes that executes some specific task assigned to it invoked by its name. If there is an argument …
Read More

C++ Null Pointer

We use a null pointer when we do not have the exact address to assign to a pointer. It is considered a good practice and …
Read More