In Java compiler，which type can be defined as identifier ( ID ) or Keyword (reserved word)?

Question

I have a simple question:
In Java Compiler, Which type of method or variables can be defined as identifier (ID) or Keyword (reserved word)?

For following example, ID

Answer 1

The Java keywords are part of the language, and are documented in the Java Language. You cannot use a keyword as an identifier . const and goto are reserved keywords, but not implemented. true, false, and null are literals; you still cannot use them as identifiers but they are not keywords.

From the linked Java tutorial, the keywords are

• abstract
• continue
• for
• new
• switch
• assert³
• default
• goto¹
• package
• synchronized
• boolean
• do
• if
• private
• this
• break
• double
• implements
• protected
• throw
• byte
• else
• import
• public
• throws
• case
• enum⁴
• instanceof
• return
• transient
• catch
• extends
• int
• short
• try
• char
• final
• interface
• static
• void
• class
• finally
• long
• strictfp²
• volatile
• const¹
• float
• native
• super
• while

¹not used

²added in 1.2

³added in 1.4

⁴added in 5.0