round()

[meena latha]

hi all

It has been said in K&B that in round(),if the number after the decimal point is greater than or equal to 0.5 then Math.round() is equal to Math.ceil()

class Maker {
  public static void main (String[] args) {
    System.out.println(Math.round(-3.6));
}}

The output is -4.
How come the output is -4 it should be -3 .Am i right.

[ramaseshan T]

To find rounded value, always use floor(value+0.5). In this case
floor(-3.6+0.5)=floor(-3.1)=-4.

Refer Math API..

[meena latha]

Thanks ramaseshan.

[trivikram Kumar]

the easiest trick is ...
Math.round(-3.5) is -3 ceil the number if -'ve fraction is <=5.
Math.round(-3.6) is -4 floor the number if -'ve fraction is >=5.
Math.round(3.5) is 4 The reverse strategy applies for +'ve fractions

i.e floor the number if +'ve fraction is <=5
& ceil the number if +'ve fraction is >5