KEYWORDS IN JAVA

The Java programming language has total of 50 reserved keywords which have special meaning for the compiler and cannot be used as variable names. Following is a list of Java keywords in alphabetical order, click on an individual keyword to see its description and usage example.

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

Some noteworthy points regarding Java keywords:

• const and goto are resevered words but not used.
• true, false and null are literals, not keywords.
• all keywords are in lower-case.

The following table shows the keywords grouped by category:

Categorys	Keyword
Access modifiers	private, protected, public
Class, method, variable modifiers	abstract, class, extends, final, implements, interface, native, new, static, strictfp, synchronized,  transient, volatile
Flow control	break, case, continue, default,  do, else, for, if, instanceof,  return,switch, while
Package control	import, package
Primitive types	boolean, byte, char, double,  float, int, long, short
Error handling	assert, catch, finally, throw,  throws, try
Enumeration	enum
Others	super, this, void
Unused	const, goto

1. //example of this keyword  

1. class Student11{  
2.     int id;  
3.     String name;  
4.       
5.     Student11(int id,String name){  
6.     this.id = id;  
7.     this.name = name;  
8.     }  
9.     void display(){System.out.println(id+" "+name);}  
10.     public static void main(String args[]){  
11.     Student11 s1 = new Student11(111,"Karan");  
12.     Student11 s2 = new Student11(222,"Aryan");  
13.     s1.display();  
14.     s2.display();  
15. }  
16. }  

Output111 Karan
       222 Aryan