what is unary operator in java

Answer 1

The unary operators requires only one operand to perform different kind of operations such as increasing/decreasing a value, negating an expression, or inverting a boolean value.
For eg.,

- the increment (++) and decrement(--) operators are unary :
int x = 0;
 int y = 0;
 y = ++x;
 System.out.println(x);
  System.out.println(y);
  }
}
// The output of this program shows that always 1 is stored in both variables i.e. the value of "x" is incremented first then it is assigned to the variable "y".

There are many more examples here :
http://www.roseindia.net/java/master-java/unary-operators.shtml

https://docs.oracle.com/javase/tutorial/java/nutsandbolts/op1.html

Answer 2

ok

Answer 3

ok very good