Can anyone pls explain about the output of this prog.

[Ritu Kapoor]

Pls look at the following code. Can anyone pls explain me the output.

   
public class TestClass
{
      public static void main(String[] args) throws Exception
      {
            int a = Integer.MIN_VALUE;
            int b = -a;
            System.out.println( a+ "   "+b);
      }
} 

The output is : -2147483648 -2147483648

[Vaibhav Chauhan]

here b should show the value '2147483648' but the maximum positive number is '2147483647'.
Actually these values lie in circular form so the desired result is 2147483648 i.e. '2147483647+1' so when we add 1 to 2147483647, the value becomes -2147483648.

try this program

int a = Integer.MIN_VALUE;    
int b = -a-1;  
System.out.println( a+ "\n"+b); 

output:
-2147483648
2147483647


i hope you got it.

[Chetan Raju]

There is no concept of overflow error/exception in integer arithmetic. When you negate the largest negative number, you get a positive number which is out of range of integer. So it wraps to the smallest no which is again the integer minimum value.