This week's book giveaway is in the Jobs Discussion forum.
We're giving away four copies of Java Interview Guide and have Anthony DePalma on-line!
See this thread for details.
The moose likes Blatant Advertising and the fly likes SJCP question Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Java Interview Guide this week in the Jobs Discussion forum!
JavaRanch » Java Forums » Other » Blatant Advertising
Bookmark "SJCP question " Watch "SJCP question " New topic

SJCP question

mohit rastogi

Joined: Jan 14, 2007
Posts: 7
I write the question Please give me the write answer for that .

class X {
public static void main(String[ ] args) {
Boolean b1 = new Boolean( true );
boolean b2 = true;
Boolean b3 = Boolean.valueOf( "FALSE" );
Boolean b4 = Boolean.valueOf( "yes" );

if ( b1 & b2 || b3 | b4)
System.out.println( "Mercury" );
System.out.println( "Mars" );

Options :

a . Mercury
b . Mars
c . Compilation fails
d . Runtime exception

this is the Question i try it on the compiler 1.5 . the correct answer is Mercury.

But I got this form some simulator where the Question answer is as follows :
c . Compilation fails

All constructions for b1 to b4 are valid. b1 is a Boolean object (created through the Boolean wrapper class) with a value of true. b2 is a boolean primitive with value as true. b3 and b4 are both Boolean objects with the same value of false. b3 and b4 are created through the static Boolean valueOf( ) method. This method accepts primitive boolean values or case-insensitive string representation of the boolean values. If you input an unrecongized boolean value or the null literal, the valueOf( ) method will simply return a Boolean object with a false value.

Nevertheless, Boolean objects created through the Boolean wrapper class cannot be used as an expression in a boolean test. A Boolean object is not the same as a boolean primitive. Therefore, the compilation fails at the if clause. Beware of such trick question.

pls any one can reply me for this question what is the correct answer for that .
I agree. Here's the link:
subject: SJCP question
It's not a secret anymore!