I've rewritten your code into a form that I think makes at least some sense:
my $amt = 4887.15;
print " Checking amnt before conversion $amt,\n";
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", $amt;
print "$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";
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)"
$ raku -e "say 4887.15e0 * 100"