Re: Question related to the use of constants

I want to know if the way perl handle constants are similar the way C handles defines

Nope. Perl handles them (more or less) the way more recent C compilers handle inline functions. When you use constant FOO => 1;, a subroutine is created in your current package like this:

sub FOO () { 1 }
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That sort of subroutine (note empty prototype and simple return value) will be considered for inlining. You can then use it anyplace you could put a subroutine, which does not include string interpolation (which is what hash lookups are).

OTOH, a #DEFINE in C is done by the preprocessor, which modifies the source code before the compiler does anything with it.

"There is no shame in being self-taught, only in not trying to learn in the first place." -- Atrus, Myst: The Book of D'ni.

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Re^2: Question related to the use of constants by BUU (Prior) on Aug 21, 2004 at 04:52 UTC
(which is what hash lookups are). That's just wrong. The only thing special about hash look ups are that barewords are special cased to be treated as a string. `sub foo { "test" } $hash{ foo } = 32; #the literal string "foo" is used as the key $hash{ foo() } = 45; #the string "test" is used $x='te'; $y='st'; $hash{ $x$y } = 32; #this is a syntax error, because it's not string i +nterpolation` [download]	[reply] [d/l]

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Re^2: Question related to the use of constants
by BUU (Prior) on Aug 21, 2004 at 04:52 UTC

(which is what hash lookups are).

sub foo { "test" }
$hash{ foo } = 32; #the literal string "foo" is used as the key
$hash{ foo() } = 45; #the string "test" is used

$x='te';
$y='st';
$hash{ $x$y } = 32; #this is a syntax error, because it's not string i
+nterpolation
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