Re: what did I just see..?

Since it hasn't been mentioned yet, note that at the cost of performance, you can get accurate calculations by adding a use bignum; to your code. Note that its scope is lexical, so you can limit the performance impact a bit by only applying it where needed in your code.

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Re^2: what did I just see..? by syphilis (Archbishop) on Mar 23, 2021 at 02:08 UTC
... you can get accurate calculations by adding a use bignum; to your code I think this is the only solution that requires no modification to the original line of code: `for ($x=0.8; $x > 0.1; $x -= 0.01) { print "$x\n"; }` It's probably worth pointing out to the OP that it works simply because bignum uses decimal (base 10) arithmetic. There are other ways to force base 10 arithmetic - eg Math::Decimal, Math::Decimal64 and Math::Decimal128. (The last 2 are a plug, and will work far more quickly than bignum.) However, they would all require some changes to the given line of code. For example: `use Math::Decimal64; for ($x = Math::Decimal64->new('0.8'); $x > '0.1'; $x -= '0.01') { pri +nt "$x\n"; } # or if one is insistent upon receiving 0.xx formatting of the values +(instead of "xxe-2") formatting: for ($x = Math::Decimal64->new('0.8'); $x > '0.1'; $x -= '0.01') { pri +nt "$x" + 0, "\n"; }` [download] Cheers, Rob	[reply] [d/l] [select]

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Re^2: what did I just see..?
by syphilis (Archbishop) on Mar 23, 2021 at 02:08 UTC

... you can get accurate calculations by adding a use bignum; to your code

for ($x=0.8; $x > 0.1; $x -= 0.01) { print "$x\n"; }

use Math::Decimal64;
for ($x = Math::Decimal64->new('0.8'); $x > '0.1'; $x -= '0.01') { pri
+nt "$x\n"; }
# or if one is insistent upon receiving 0.xx formatting of the values 
+(instead of "xxe-2") formatting:
for ($x = Math::Decimal64->new('0.8'); $x > '0.1'; $x -= '0.01') { pri
+nt "$x" + 0, "\n"; }
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