Re (tilly) 1: Integer detection concept

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Re: Re (tilly) 1: Integer detection concept by larryk (Friar) on May 15, 2001 at 16:10 UTC
I'm not computer whizzy enough to explain in detail but I think that if you ask a computer to store a floating point number which is obtained as a fraction (eg. `$a = 1/3;`) then you get 0.333333333333333 (not 0.3 recurring) to however many decimal places. If yuo then operate on this number, because it does not remain a fraction, the results are "rounded". So to compare the result of iakobski's sqrt and subsequent squaring to 1/3 would not match using `==`. In this case it is only integers (whole numbers - no decimal places) which are being discussed so they must be stored more sensible and a numerical comparison (`==`) will be more efficient than comparing the two strings (especially on large numbers, possibly several hundreds of thousands of times through a loop). I think essentially the eq and ne have to go through both "strings" a character at a time and compare them but `==` or `!=` can just say these numbers are('nt) the same. larryk ---------------------------------------------------- $less->{'chars'} = `"time in the pub" \| more`; # :-D [download]	[reply] [d/l] [select]

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Re: Re (tilly) 1: Integer detection concept
by larryk (Friar) on May 15, 2001 at 16:10 UTC

$a = 1/3;

==

In this case it is only integers (whole numbers - no decimal places) which are being discussed so they must be stored more sensible and a numerical comparison (==) will be more efficient than comparing the two strings (especially on large numbers, possibly several hundreds of thousands of times through a loop).

I think essentially the eq and ne have to go through both "strings" a character at a time and compare them but == or != can just say these numbers are('nt) the same.

larryk

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$less->{'chars'} = `"time in the pub" | more`; # :-D
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