Type Of Question in Exam

[vinay jain]

Hello Everyone, while going thru the mock exam at Jtips.net I came across this question.
<pre>
Given:
class Q14 {
public static void main(String[] args) {
int intNumber = 123456789;
float floatNumber = intNumber;
int x = (int)floatNumber;
System.out.println(intNumber - x);
System.out.println(intNumber == x );
}
}
Choose 2 answers.
1.Prints 0 and true .
2.Prints 0 and false.
3.Prints (some number due to loss of precision) and true.
4.Prints some integer due to loss of precision and false.
</pre>
Can anyone please tell me can we expect this kind of questions in the certification exam as I think this kind of questions should not come into exam which asks you questions like at what range the int -> float conversion will loose some precision?
Any comments?

[Jose Botella]

I guess this very question is perfect for the exam because it test your knowlegde of numeric values. I think any SJCP should know the result of the program. I wouldn't find reasonable they will ask the exact diference though.

[SIMONS]

How can I tell which number will cause loss of precision in this case? If I replace 123456789 with:
5 -> no loss
500,000,000 -> no loss
500,000,001 -> loss
500,000,002 -> loss
500,000,010 -> loss
500,000,020 -> no loss
I cannot see a general rule of thumb. Please shed some lights.
The code that I use to test this:
public class Test {
public static void main(String[] args) {
int intNumber = (new Integer(args[0])).intValue();
float floatNumber = intNumber;
System.out.println("min: " + Math.min(
Integer.MAX_VALUE, intNumber));
System.out.println(floatNumber);
int x = (int)floatNumber;
System.out.println("x is " + x + " so " + (intNumber - x));
System.out.println(intNumber == x );
}
}