Reg. rint()

[Angela Narain]

How does the rint() method work ?
As per the API

public static double rint(double a)
Returns the double value that is closest in value to a and is equal to a mathematical integer. If two double values that are mathematical integers are equally close to the value of the argument

[Amit Agrawal]

copy pasted what is written in the API. whats confusing you (please point out)?

public static double rint(double a)
Returns the double value that is closest in value to a and is equal to a mathematical integer. If two double values that are mathematical integers are equally close to the value of the argument, the result is the integer value that is even. Special cases:
If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.
Parameters:
a - a double value.
Returns:
the closest double value to a that is equal to a mathematical integer.

[Angela Narain]

Can someone explain it with reference to an example.
thanks

[Roopa Bagur]

Which class in the API does this method belong to?

Originally posted by Amit Agrawal*:
copy pasted what is written in the API. whats confusing you (please point out)?

public static double rint(double a)
Returns the double value that is closest in value to a and is equal to a mathematical integer. If two double values that are mathematical integers are equally close to the value of the argument, the result is the integer value that is even. Special cases:
If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.
Parameters:
a - a double value.
Returns:
the closest double value to a that is equal to a mathematical integer.

[Amit Agrawal]

Here is an example for the same, Please lemme know if it is still not clear.

// rint (a method of Math class).
// basic purpose, returns nearest possible integer (as double).
System.out.println(Math.rint(5.2)); // would return 5.0
System.out.println(Math.rint(5.8)); // would return 6.0

// special case 1.
// if tow integers (upper and lower) are equally close to the number passed than it returns even value amogest them.
System.out.println(Math.rint(7.5)); // returns 8.0 dispite being equally close to 7.0 and 8.0 cause 8.0 is even.

// special case 2.
// returns same as passed, if argument passed is already an integer, Nan, infinity.
System.out.println(Math.rint(10)); // returns 10.0
System.out.println(Double.NaN); // returns NaN
System.out.println(Double.POSITIVE_INFINITY); // returns Infinity
System.out.println(Double.NEGATIVE_INFINITY); // returns -Infinity.

Originally posted by Angela Narain:
Can someone explain it with reference to an example.
thanks

Originally posted by Roopa Bagur
Which class in the API does this method belong to?

As you might have guessed, it belongs to Math class.
[This message has been edited by Amit Agrawal* (edited September 18, 2001).]

[Roopa Bagur]

Does this mean that if you pass 6.5 rint() will return 6 instead of 7 since 6 is even ?

Originally posted by Amit Agrawal*:
[B]Here is an example for the same, Please lemme know if it is still not clear.

// rint (a method of Math class).
// basic purpose, returns nearest possible integer (as double).
System.out.println(Math.rint(5.2)); // would return 5.0
System.out.println(Math.rint(5.8)); // would return 6.0

// special case 1.
// if tow integers (upper and lower) are equally close to the number passed than it returns even value amogest them.
System.out.println(Math.rint(7.5)); // returns 8.0 dispite being equally close to 7.0 and 8.0 cause 8.0 is even.

// special case 2.
// returns same as passed, if argument passed is already an integer, Nan, infinity.
System.out.println(Math.rint(10)); // returns 10.0
System.out.println(Double.NaN); // returns NaN
System.out.println(Double.POSITIVE_INFINITY); // returns Infinity
System.out.println(Double.NEGATIVE_INFINITY); // returns -Infinity.

Originally posted by Roopa Bagur
Which class in the API does this method belong to?

As you might have guessed, it belongs to Math class.
[This message has been edited by Amit Agrawal* (edited September 18, 2001).][/B]

[Angela Narain]

Thanks Amit for the explanation. Its very clear to me now..
Yes Roopa, the result of Math.rint(6.5) will be 6.0
as both 6.0 and 7.0 are equally close but as 6.0 is even
so it is taken.