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5.6 Context Considerations
We have now discussed all the different ways you can use variables in
list and scalar context. At this point, it might be helpful to review
all the ways we have used variables in different contexts. The table
that follows identifies many of the ways variables are used in Perl.
| Expression | Context | Variable | Evaluates to |
$scalar | scalar | $scalar, a scalar |
the value held in $scalar
|
@array | list | @array, an array |
the list of values (in order) held in @array
|
@array | scalar | @array, an array |
the total number of elements in @array (same as
$#array + 1)
|
$array[$x] | scalar | @array, an array |
the ($x+1)th element of @array
|
$#array | scalar | @array, an array |
the subscript of the last element in @array (same as
@array -1)
|
@array[$x, $y] | list | @array, an array |
a slice, listing two elements from @array (same as
($array[$x], $array[$y]))
|
"$scalar" | scalar (interpolated) | $scalar, a scalar |
a string containing the contents of $scalar
|
"@array" | scalar (interpolated) | @array, an array |
a string containing the elements of @array, separated by
spaces
|
%hash | list | %hash, a hash |
a list of alternating keys and values from %hash
|
$hash{$x} | scalar | %hash, a hash |
the element from %hash with the key of $x
|
@hash{$x, $y} | list | %hash, a hash |
a slice, listing two elements from %hash (same as
($hash{$x}, $hash{$y})
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