Unary Operator

1)

class A 
{
 public static void main(String[] args) 
 {
  int i=0;
  System.out.println(i++);
  System.out.println(i);
 }
}

OP:
0
1
---------------------------------------------------------------------------
2)

class A
{
 public static void main(String[] args) 
 {
  int i=0;
  System.out.println(++i);
  System.out.println(i);
 }
}

OP:
1
1
---------------------------------------------------------------------------
3)

class A 
{
 public static void main(String[] args) 
 {
  int i=1;
  System.out.println(i++);
  System.out.println(i);
  i=1;
  System.out.println(i--);
  System.out.println(i);
  i=1;
  System.out.println(++i);
  System.out.println(i);
  i=1;
  System.out.println(--i);
  System.out.println(i);
 }
}

OP:
1
2
1
0
2
2
0
0
---------------------------------------------------------------------------
4)

class A 
{
 public static void main(String[] args) 
 {
  int i=1;
  System.out.println(i++);
  System.out.println(i);
  int i=0;
  System.out.println(i--);
  System.out.println(i);
 }
}

-->Compilation error
A.java:8: i is already defined in main(java.lang.String[])
int i=0;
^
1 error

---------------------------------------------------------------------------
5)

class G 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=i++;
      //usage value    0
      //final value    1
  System.out.println(i);
  System.out.println(j);
 }
}

OP:
1
0
---------------------------------------------------------------------------
6)

class A
{
 public static void main(String[] args)
 {
  int i=0;
  System.out.println(i++ + i + --i + ++i + i);
  System.out.println(i);
  //usage            0     1    0     1    1 =sum of expression =3
  //final            1     1    0     1    1 =final value of  i =1
 }
}

OP:
3
1
---------------------------------------------------------------------------
7)

class G 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=++i;
  System.out.println(i);
  System.out.println(j);
 }
}

OP:
1
1
---------------------------------------------------------------------------
8)

class G 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=i++ + i;
  //usage value 0  + 1
  //final value 1    1
  System.out.println(i);
  System.out.println(j);
 }
}

OP:
1
1
---------------------------------------------------------------------------
9)

class G 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=i++ + ++i + i++ + ++i ;
        //Usage value  0     2     2    4
 //final value  1     2     3    4
  System.out.println(i);
  System.out.println(j);
 }
}

OP:
4
8
---------------------------------------------------------------------------
10)

class G 
{
 public static void main(String[] args) 
 {
  int i=0;
                int j=i++ + i++ + i++ + i ;
  //usage 0 + 1     2     3
  //final 1   2     3     3
  System.out.println(i);
  System.out.println(j);
 }
}

OP:
3
6

---------------------------------------------------------------------------
11)
-->MAKE UNCOMMENT REST AND CHECK OUTPUT

class G
{
 public static void main(String[] args) 
 {
  int i=0;
                i=i++;     // 0
                //i=i--;   // 0
                //i=++i;   // 1
                //i=--i;   //-1
  System.out.println(i);
 }
}

OP:
0

--------------------------------------------------------------------------
12)

class H 
{
 public static void main(String[] args) 
 {
  int i=10;
  System.out.println(test(i));
  System.out.println(i);
 }
 static int test(int i)
 {
  return i++;       //will return 10,post increment will not reflect to method
      // return ++i; --> will return 11
 }
}

OP:
10
10
---------------------------------------------------------------------------
13)

class H 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=i++ + test(i++) + i++ + i;
 //usage value  0      1/1        2    3
 //final value  1      2          3    3

  System.out.println(i);
  System.out.println(j);
 }
 static int test(int i)
 {
  return i++;  //post increment of i will not reflect in main method
 }
}

OP:
3
6
---------------------------------------------------------------------------
14)

class H 
{
 public static void main(String[] args) 
 {
  int i=0;
         int j=i++ + test(i) + i++ + i;
            //usage    0      1/1      1    2
            //final    1      1        2    2
  System.out.println(i);
  System.out.println(j);
 }
 static int test(int i)
 {
  return i++;  //post increment of i will not reflect in main method
 }
}

OP:
2
4
---------------------------------------------------------------------------
15)

class H 
{
 public static void main(String[] args) 
 {
  int i=0;
  int j=i++ + test1(i++) + test2(++i);
 //usage value  0       1/2           3
 //final value  1       2             3
  System.out.println(i);
  System.out.println(j);
 }
 static int test1(int i)
 {
  return ++i; 
 }
 static int test2(int i)
 {
  return i++;
 }  
}

OP:
3
5