Re: expected 0 not result gotten

[quester]

To answer the second part of your question:

Digging into this I tried something "simplier" and got more confused:

perl -e 'print ((.0425*2) + .0025 ) - ((.0425*2) + .0025 ); print $/;'

just bring the perlrun option -w (warnings) to the rescue:

$ perl -we 'print ((.0425*2) + .0025 ) - ((.0425*2) + .0025 ); print $
+/;'
print (...) interpreted as function at -e line 1.
Useless use of subtraction (-) in void context at -e line 1.
0.0875

That can be fixed with either extra parens or a plus sign:

$ perl -we 'print (((.0425*2) + .0025 ) - ((.0425*2) + .0025 )); print
+ $/;'
0

$ perl -we 'print +((.0425*2) + .0025 ) - ((.0425*2) + .0025 ); print 
+$/;'
0

There is a explanation of this in the perldoc for print:

"Be careful not to follow the print keyword with a left parenthesis unless you want the corresponding right parenthesis to terminate the arguments to the print; put parentheses around all arguments (or interpose a + , but that doesn't look as good)."

[Anonymous Monk]

surprising but true, i get something like, $ perl -we 'my $x = (.0425 * 2) + .0025; print $x - (.042+5 * 2) - .0025, $/;' -9.957 i am using perl 5.8.8

[quester]

Do you mean that it surprises you that

.0425*2

is different than

.042+5*2

Um... wow... really?