CHAPTER 3: Lexical Structure

Previous

Java Language

Index

Next

3.9 Keywords

The following character sequences, formed from ASCII letters, are reserved for use as keywords and cannot be used as identifiers (S3.8):

Keyword: one of

	abstract	default	if	private	throw

	boolean	do	implements	protected	throws

	break	double	import	public	transient

	byte	else	instanceof	return	try

	case	extends	int	short	void

	catch	final	interface	static	volatile

	char	finally	long	super	while

	class	float	native	switch

	const	for	new	synchronized

	continue	goto	package	this

The keywords const and goto are reserved by Java, even though they are not currently used in Java. This may allow a Java compiler to produce better error messages if these C++ keywords incorrectly appear in Java programs.

While true and false might appear to be keywords, they are technically Boolean literals (S3.10.3). Similarly, while null might appear to be a keyword, it is technically the null literal (S3.10.7).