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One can predeclare subroutines with
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sub name; # may be used before implementation appears
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Subroutines may be defined anonymously:
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sub newprint {
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my $x = shift;
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# return anonymous subroutine:
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return { my $y=shift; print "$x $y!\n"; };
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}
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$h = newprint("Howdy"); # store anonymous subroutine
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&$h("World"); # call anonymous subroutine, which prints
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"Howdy World!"
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Note the $x in anonymous subroutine is private and retains value "Howdy" in $h even when newprint is called again:
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$g = newprint("Hello"); # $g has separate instance of $x
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