On Aug 25, 2005, at 3:22, Jayvee Vibar wrote:
Is there an IsNumber() function in perl? I'm looking for a way to
determine
of a given $variable is numeric or not. Thanks.
If you need to know whether it looks like a number there are a few
ways, see
perldoc -q determine
If on the other hand what you need is a way to know whether the
underlying type is really numeric (for instance because you are going
to use it as operand of & on variables that might come as strings
("&" has a dual nature)) then normally one just enforces it explicitly:
sub subroutine_whose_args_are_integers_but_might_come_as_strings {
my ($x, $y) = @_;
$x = 0 + $x; # ensure $x has underlying integer type
$y = 0 + $y; # ensure $y has underlying integer type
my $z = $x & $y; # safe, & acting as bitwise AND for sure
# ...
}
-- fxn
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