Re^2: int($x) gives strange result

In general that's a very bad idea. If the number is larger, multiplying by 100.1 will severely skew the result:

$ perl -wle ' my $x = 123456.15; print +(int($x*100.1))/100;'
123579.6
[download]

So it turned 123456.15 into 123579.6 just to get rid of rounding errors - and produced errors which are about a thousand times larger.

Instead you can add (not multiply) a small constant before calling int:

$ $ perl -wle ' my $x = 1.15; print +(int($x*100 + 1e-8))/100;'
1.15
[download]

Depending on the range of the used numbers you'd have to think a bit more about the size of the small number you add.

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Re^3: int($x) gives strange result by SFLEX (Chaplain) on Aug 24, 2009 at 08:52 UTC
++moritz I was playing with it to the thousandth and found about the same "BAD" result: `my $x = 1.159; print +(int($x*100.1))/100;` [download] What did the Pro-Perl programmer say to the Perl noob? You owe me some hair.	[reply] [d/l]