Keywords
info
Keywords are simple english words which are having predefined meaning in Java Programming Language.
Key Points:
- Meaning of these keywords can't be modified.
- Keywords are also called Reservered Words.
- All keywords are defined in lower case.
- We can't use the keywords as names for variables, methods, classes, or any other identifiers.
- true, false, null are not keywords, but reserverd as Literals.
- There are 67 keywords defined upto Java 24.
- const and goto are the keywords but no implementation available. You can't use these keywords in Java Program.
| Category | Java Keywords |
|---|---|
| Data Types | byte, short, int, long, float, double, char, boolean, void |
| Class and Object | class, interface, enum, record, new, this, super, instanceof |
| Access Modifiers | public, private, protected |
| Other Modifiers | static, final, abstract, synchronized, native, strictfp, transient, volatile, sealed, non-sealed |
| Packages & Modules | package, import, module, requires, exports, opens, provides, uses, with |
| Control Statements | if, else, switch, case, default, while, do, for, break, continue, return, yield |
| Exception Handling | try, catch, finally, throw, throws |
| Flow & Behavior | assert, return, yield |
| Reserved (not used) | const, goto |
📝 Additional Notes:
-
Literals: true, false, and null are literals, not keywords.
-
Contextual Keywords:
var— introduced in Java 10 for local variable type inference (not a reserved keyword)yield— Java 14+ switch expressions (reserved keyword now)sealed,non-sealed,permits— Java 15+ (reserved keywords)