On Tue, Nov 25, 2008 at 1:03 PM, Ludwig Isaac Lim <[EMAIL PROTECTED]>wrote:
>
> Hi:
>
> Is there a better way of rewriting the following perl statement?
> (method 1)
> @arr = split /\s+/, $str, $num_elem;
>
> die("Should have $num_elem element") if ( (scalar @arr) != $some_number);
You may remove "scalar". "!=" operates only on scalar values, so the named
array above will be evaluated in scalar context even without "scalar".
>
> $var1 = @arr[0];
> $var2 = @arr[1];
@array[index] is wrong. The correct sigil for scalar values is "$",
even when the scalar is part of an array or hash. That was changed in
Perl 6 though, because many programmers get confused by that. :-)
...
> ...
> $varn [EMAIL PROTECTED]<number>];
>
> (method 2)
>
> ($var1,$var2,$var3) = split /\s+/,@arr,3;
>
Passing an array as the second argument to split() and expecting split()
to return a list is wrong. @arr will be evaluated in scalar context. Thus,
what will be passed to split() is the length of @arr.
> But using method2 2, it seems the only way to check if 3 elements are
> returned by split is have
> something like this (I maybe wrong):
>
> if (!(defined($var3))) {
> die("less than 3 elements returned");
> }
>
>
> Any better way of combining the brevity of method 2 and the error
> checking of method 1?
>
Try
@array = split(...);
die if @array != $required_num_of_elts;
($var1, $var2, ...) = @array;
HTH
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