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q on wrapper classes

JayaSiji Gopal
Ranch Hand

Joined: Sep 27, 2004
Posts: 303
What is the output of trying to compile and run the following code?
(Select one correct answer)
--------------------------------------------------------------------------------

public class Test041
{
static double d;
static float f;

public static void main(String args[])
{
compare(Long.MAX_VALUE, Long.MAX_VALUE );
compare(Integer.MAX_VALUE, Integer.MAX_VALUE );
compare(Character.MAX_VALUE, Character.MAX_VALUE);
compare(Short.MAX_VALUE, Short.MAX_VALUE );
compare(Byte.MAX_VALUE, Byte.MAX_VALUE );
}

static void compare(double d, float f)
{
if (f == d) System.out.print(" equal" );
else System.out.print(" unequal");
}
}

--------------------------------------------------------------------------------

A: unequal equal equal equal equal
B: equal unequal equal equal equal
C: equal equal unequal equal equal
D: equal equal equal unequal equal
E: equal equal equal equal unequal

I could not answer this q, can someone plz explain


SCJP 1.4, SCWCD 1.4<br /> <br />Thanks in advance!<br />Jayashree.
sanjeevmehra mehra
Ranch Hand

Joined: Aug 21, 2004
Posts: 75

What is the output of trying to compile and run the following code?
(Select one correct answer)



A: unequal equal equal equal equal
B: equal unequal equal equal equal
C: equal equal unequal equal equal
D: equal equal equal unequal equal
E: equal equal equal equal unequal

I could not answer this q, can someone plz explain

Jayashree, pls. use CODE tag.


thanks & regards,<br />Sanjeev.
sanjeevmehra mehra
Ranch Hand

Joined: Aug 21, 2004
Posts: 75
A. is ans.
Long is 64 bit. float is 32 bit and value would be truncated & (changed automatically) so that would result unequal.
rest of data type used are "less or equal" to 32 bit, value would be same for float(32 bits) & double (64 bits).
Federico Zuppa
Greenhorn

Joined: Nov 23, 2004
Posts: 7
Something weird: I executed and printed the numbers in the method (see below) and for the Long numbers, it resulted in "equal" (though I see they are different). The Integers results in unequal (I read that "widening conversion of an int or long to a float may result in loss of precision however the new float value will be the correctly rounded" (http://www.janeg.ca/scjp/oper/conversions.html) so this should be allright).

So correct option is B ?

9.223372036854776E18
9.223372E18
equal
2.147483647E9
2.14748365E9
unequal
 
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subject: q on wrapper classes