You can’t use keyword as identifier in your Java programs, its reserved words in Java library and used to perform an internal operation.
| 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 | true | false | |
| null |
true, false and null are not reserved words but cannot be used as identifiers, because it is literals of built-in types.
