Reserved words

Reserved words:-

In java some identifiers are reserved to associate some functionality or meaning such type of reserved identifiers are called reserved words.

Diagram:-

Reserved words for flow control:
1) if
2) else
3) switch
4) case
5) default
6) for
7) do
8) while
9) break
10) continue
11) return

Keywords for modifiers:
1) public
2) private
3) protected
4) static
5) final
6) abstract
7) synchronized
8) native
9) strictfp  (1.2 version)
10) transient
11) volatile

Keywords for exception handling:
1) try
2) catch
3) finally
4) throw
5) throws
6) assert   (1.4 version)

Class related keywords:
1) class
2) package
3) import
4) extends
5) implements
6) interface

Object related keywords:
1) new
2) instanceof
3) super
4) this

Void return type keyword:

If a method won’t return anything compulsory that method should be declared with the
void return type in java but it is optional in C++.

1) void

Unused keywords:

1) goto: Create several problems in old languages and hence it is banned in java.
2) Const: Use final instead of this.

By mistake if we are using these keywords in our program we will get compile time
error.

Reserved literals:
1) true values for boolean data type.
2) false
3) null  (default value for object reference.)
Enum:
This keyword introduced in 1.5v to define a group of named constants

Example:
enum Beer{
KF, RC, KO, FO;
}
Note: All reserved words in java contain only lowercase alphabet symbols.
New keywords are:
Strictfp———–1.2
Assert————-1.4
Enum————–1.5
Q Which of the following list contains only java reserved words?
1) final, finally, finalize (invalid)                       // here finalize is a method in Object class.
2) throw, throws, thrown(invalid)                   // thrown is not available in java
3) break, continue, return, exit(invalid)        // exit is not reserved keyword
4) goto, constant(invalid)                                 // here constant is not reserved keyword
5) byte, short, Integer, long(invalid)            // here Integer is a wrapper class
6) extends, implements, imports(invalid)// imports keyword is not available in java
7) finalize, synchronized(invalid)               // finalize is a method in Object class
8) instanceof, sizeOf(invalid)                     // sizeOf is not reserved keyword
9) new, delete(invalid)                                // delete is not a keyword
10) None of the above(valid)
Q Which of the following are valid java keywords?
1) public(valid)
2) static(valid)
3) void(valid)
4) main(invalid)
5) String(invalid)
6) args(invalid)