Unary operators in java

Let’s learn unary operators in java.

Unary operators in java

Unary operator needs only one operand to increment, decrement, etc. Here are various unary operators,

Logical complement operator (!): reverses logical state or value of operand. If the value is false, it converts value to true and vice versa.
Unary minus (-): converts positive value to negative value.
Increment (++): increments value of an integer. post and pre-increment.
Decrement (- -): decrements value of an integer. post and pre-decrement.
Unary plus (+): operator represents positive value. That is it makes all bits inverted, every 0 to 1 and every 1 to 0.

Here’s an example on ‘NOT’ (!) operator.

public class JavaUnaryOperator
{
   public static void main(String[] args)
   {
      boolean bool = true;
      int a = 14, b = 5;
      System.out.println("Before using NOT operator(!): " + bool);
      System.out.println("a = " + a);
      System.out.println("b = " + b);
      System.out.println("After using using NOT operator(!): " + !bool);
      System.out.println("!(a < b) = " + !(a < b));
      System.out.println("!(a > b) = " + !(a > b));
   }
}

Output:

Before using NOT operator(!): true
a = 14
b = 5
After using using NOT operator(!): false
!(a < b) = true !(a > b) = false

Here’s an example on unary minus operator(-).

public class JavaUnaryOperator
{
   public static void main(String[] args)
   {
      int a = 5;
      System.out.println("Given number : " + a);
      a = -a;
      System.out.println("After using unary minus operator(-) : " + a);
   }
}

Output:

Given number : 5
After using unary minus operator(-) : -5

Increment (++) operator increments value of an integer and this operator can be used in two ways post-increment and pre-increment.

Post-increment operator: If increment operator is placed after variable name, then value is first assigned and then incremented.

Example:

class JavaUnaryOperator 
{
   public static void main(String[] args) 
   {
      int a = 6;
      int b = a++;
      System.out.println(b);
   }
}

Output:

Pre-increment operator:

If increment operator is placed before variable name, then value is incremented first and then assigned.

Let’s see an example on pre-increment operator.

class JavaUnaryOperator 
{
   public static void main(String[] args) 
   {
      int a = 6;
      int b = ++a;
      System.out.println(b);
   }
}

Output:

Decrement operator(- -): decrements value of an integer and this operator in two ways post-decrement and pre-decrement.

Post-decrement operator: If decrement operator is placed after variable name, then value is first assigned and then decremented.

Example: a – –

class JavaUnaryOperator 
{
   public static void main(String[] args) 
   {
      int a = 6;
      int b = a--;
      System.out.println(b);
   }
}

Output:

Pre-decrement operator: If decrement operator is placed before variable name, then value is decremented first and then assigned.

Let’s see an example on pre-decrement operator.

class JavaUnaryOperator 
{
   public static void main(String[] args) 
   {
      int a = 6;
      int b = --a;
      System.out.println(b);
   }
}

Output: