About Question com.enthuware.ets.scjp.v6.2.286 :

[ETS User]

The Question stated:

Code: Select all

What will the following code print?


  int i = 0;
  int j = 1;
  if( (i++ == 0) [b]&&[/b] (j++ == 2) )
  {
     i = 12;
  }
  System.out.println(i+" "+j);

In the explanation the answer stated:

Code: Select all

This question is based on 2 concepts:

1. i = = ++j is not same as i = = j++;
In the case of i == ++j, j is first incremented and then compared with i. While in the case of i == j++;, j is first compared with i and then incremented.

2. The | operator, when applied for boolean operands, ensures that both the sides are evaluated. This is opposed to || which does not evaluate the RHS if the result can be known by just evaluating the LHS.

Now, let us see the values of i and j at each step:

int i = 0;
int j = 1;
if( (i++ == 0) [b]&[/b] (j++ == 2) )    //compare i with 0 and increment i => returns true and i becomes 1. Evaluate next condition:
		//compare j with 2 and increment j => return false and j becomes 2.
		//true & false returns false so i= 12 is not executed.
{
	i = 12;
}
System.out.println(i+" "+j)); //print 1 and 2

This is not the same. The answer should be: 12 1 in stead of 1 2

[admin]

Hello,
I just ran the code and it prints 1 2 as stated. Could you please specify why it should print 12 1?

HTH,
Paul.

[Guest]

yes, the explanation is misleading. The answer ist still correct but for a differetn reason: the && operator does not ensure that both the sides are evaluated. But in this case it needs to evaluate the second side also as the first side comes out as true.

[admin]

I see the problem. You are right. The explanation is not for this question. This has now been fixed.

thank you for your feedback!