quick question,why int turns to float

fnever has asked for the wisdom of the Perl Monks concerning the following question:

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Re: quick question,why int turns to float by ikegami (Patriarch) on Jun 23, 2009 at 00:38 UTC
Because 1/10 is a periodic number in binary, it can't be stored exactly by a computer. Either round the number, or work with integers: `for (0..99) { my $i = $_/100; print("$i\n"); }` [download]	[reply] [d/l]
Re: quick question,why int turns to float by toolic (Bishop) on Jun 23, 2009 at 00:32 UTC
The 2nd iteration through the 'for' loop, `$i` is set to 0.01, which is a floating point value. If you want to control the output, you can use printf: `perl -e 'for($i=0;$i<10;$i+=0.01){printf "%.2f\n", $i}' ... 9.97 9.98 9.99` [download]	[reply] [d/l] [select]
Re: quick question,why int turns to float by Anonymous Monk on Jun 23, 2009 at 00:45 UTC
See Re: Explain floating point arithmetic result My floating point comparison does not work. Why ?, Why do floating point numeric equality/inequality tests fail mysteriously?, Simple math gone wrong, and various more nodes that you find by searching for "floating point", also What Every Engineer Needs To Know About Floating Point.	[reply]
Re: quick question,why int turns to float by fnever (Initiate) on Jun 23, 2009 at 00:48 UTC
is that mean i should migrate all my codes from "print" to "printf"...? it's tough:(	[reply]
Re^2: quick question,why int turns to float by graff (Chancellor) on Jun 23, 2009 at 03:10 UTC
i should migrate all my codes from "print" to "printf"...? Only those print statements that involve floating-point values, and only when you really care about how the output looks (which probably should be most of the time, when it involves floats). As for how tough it is, you only need to fix existing code once, and you'll be better off than you would be if you didn't fix it, don't you think? Also, now you know how to do it right the first time whenever you write new code.	[reply]