The unary operators requires only one operand to operate on, it can perform operations such as incrementing or decrementing value by one, negating a value or inverting a value of a boolean expression.
The unary operators use the following symbols:
+
unary plus operator; indicates positive value
-
unary minus operator; negates a value
++
unary increment operator; increments value by one
--
unary decrement operator; decrements value by one
!
unary logical complement operator; inverts a boolean value
package org.kodejava.example.fundamental;
public class UnaryOperatorsDemo {
public static void main(String[] args) {
int result = +10; // result = 10
System.out.println("result = " + result);
result--; // result = 9
System.out.println("result = " + result);
result++; // result = 10
System.out.println("result = " + result);
result = -result; // result = -10;
System.out.println("result = " + result);
//
// The increment and decrement operators can be applied
// before (prefix) or after (postfix) the operand. Both
// of them will increment or decrement value by one. The
// different is that the prefix version evaluates to the
// incremented or decremented value while the postfix
// version evaluates to the original value;
//
--result;
System.out.println("result = " + result);
++result;
System.out.println("result = " + result);
boolean status = result == -10; // status = true
System.out.println("status = " + status);
status = !status; // status = false;
System.out.println("status = " + status);
}
}