Re^3: Padding with sprintf changing number

[syphilis]

I've rewritten your code into a form that I think makes at least some sense:

use strict;
use warnings;

my $amt = 4887.15;

print " Checking amnt before conversion $amt,\n";
        $amt= sprintf("%.2f",$amt);
        print " Checking amnt after rounding $amt,\n";
        $amt = $amt*100;
        print " Checking amnt after conversion $amt,\n";
        printf "Checking the EXACT value of amnt: %.17g\n", $amt;

amnt($amt);

sub amnt
{
my $amount=$_[0];
$amount=int($amount);
print  "$amount i m checking amount before padding,\n";
#my $padamnt = sprintf("%016.0f",$amount);---> currently commented to 
+check integer effect.
my $padamnt = sprintf("%016d",$amount);

print  "$padamnt i m checking amount after padding,\n";
 return $padamnt;
}

When I run that script, I get:

 Checking amnt before conversion 4887.15,
 Checking amnt after rounding 4887.15,
 Checking amnt after conversion 488715,
Checking the EXACT value of amnt: 488714.99999999994
488714 i m checking amount before padding,
0000000000488714 i m checking amount after padding,

Note that I've added a line of code that demonstrates that the EXACT value of $amt is NOT 488715.
Perl's print() function frequently fails to produce an accurate representation of floating point values - and that's what is happening here.

That output I'm seeing is as I expect.
Which is the line of output that you don't understand ?

You need to stay alert to this aspect of perl's print() function.
Neither python3 nor raku are afflicted with such a poorly designed implementation:

$ python3 -c "print(4887.15 * 100)"
488714.99999999994

$ raku -e "say 4887.15e0 * 100"
488714.99999999994

Cheers,
Rob

[choroba]

> Neither python3 nor raku

But

$ python2 -c 'print(4887.15 * 100)'
488715.0

[syphilis]

Yes, I had good reason to avoid mentioning python2's print() implementation ;-)
It apparently rounds to even fewer decimal digits than perl5:

$ python2 -c 'print 2 ** 0.5'
1.41421356237

$ perl -le 'print 2 ** 0.5'
1.4142135623731

At least they've done something about it.
Maybe perl7 will do the same.

Cheers,
Rob