Re: syntax for calling a function

The first is preferred and the second is deprecated.

Using the ampersand allows you to call a function without parentheses:

&foo;
sub foo { print "Hello\n" }
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Perl will interpret a bareword as a subroutine call with no arguments, but then you have to make sure that perl knows your bareword is a subroutine:

foo;  # does not call foo()
sub foo { print "Hello\n" }
foo;  # calls foo()
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Comment on Re: syntax for calling a function Select or Download Code

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Re^2: syntax for calling a function by TGI (Parson) on Jun 27, 2008 at 23:20 UTC
Be very careful with `&foo;`. This is a powerful, but dangerous way to call a function and should only be done when the special semantics are intended. Powerful? Dangerous? Special semantics? This form of sub call will automagically grab the current `@_` for its arguments. Combine that with Perl's pass by reference subroutines and serious weirdness may ensue. See Messing with @_ for an example of how this can be used and/or abused. TGI says moo	[reply]
Re^2: syntax for calling a function by alexm (Chaplain) on Jun 27, 2008 at 19:08 UTC
`&foo; sub foo { print "Hello\n" }` [download] ~~Don't forget that the following calls are identical~~: `&foo; &foo(@_); foo(@_);` [download] Therefore, `&foo;` should be used with care (passing `@_` explicitly is much more friendly, IMHO). Update: chromatic is right, I should've checked perlsub before posting.	[reply] [d/l] [select]
Re^3: syntax for calling a function by chromatic (Archbishop) on Jun 27, 2008 at 19:11 UTC
Don't forget that the following calls are identical: They aren't, though. The leading `&` explicitly bypasses any prototype checking. `&foo(@_)` may be very different from `foo(@_)`.	[reply] [d/l] [select]