>> returns "true" or "false" (1 or '') and in list context it returns the
>> contents of any capturing parentheses in the pattern.
>>
>> The expression:
>>
>> ( $ptypeline =~ /movable.+(sine|geo|radial|ortho)/i
>> )[ 0 ]
>>
>> is a list slice so the regular expression is in list context but the slice is
>> a single value so the expression is a scalar.
>>
>> The || operator will only work with scalar values, not with lists, so this
>> works because the list has been converted to a scalar with the list slice.
>>
>> John
>
> ********************************************
> the list context represents everything between the / /
> and the slice context represents [ 0 ] which is
> assigned as a scalar to $ptypeline.
>
> Correct?
Any time you surround something with parenthesis () it is considered "list
context", i.e.
Scalar context: $a = $ptypeline =~ /movable.+(sine|geo|radial|ortho)/i;
In scalar context, perl is trying to assign a scalar to $a. In scalar
context that expression returns a 1 or 0 depending on whether it was able to
find that regular expression inside of $ptypeline. (Or if I had a /gi at
the end it would return the number of matches it found).
List context: @a = ($ptypeline =~ /movable.+(sine|geo|radial|ortho)/i);
This is list context, meaning that perl is trying to get a list out of that
expression. In list context, that expression returns whatever items it
found in sets of parenthesis -- in this case, if ptypeline had "ortho", @a
would be ("ortho").
I'm learning...
- B
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