Re^3: using shift and $

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Re^4: using shift and $_ in loop by leocharre (Priest) on Oct 21, 2009 at 20:26 UTC
Don't clobber your caller's variables.. so.. in .. `sub a { @_; $_; }` [download] $_ is .. what of the caller? And am I to understand that in sub a, messing with @_, regardless if the caller passed any references as arguments, is potentially messing with the caller's arguments? (thank you for your patience here)	[reply] [d/l]
Re^5: using shift and $_ in loop by ikegami (Patriarch) on Oct 21, 2009 at 20:34 UTC
$_ is .. what of the caller? `$_` is `$_`. No telling how the caller is using it. And am I to understand that in sub a, messing with @_, regardless if the caller passed any references as arguments, is potentially messing with the caller's arguments? Easy to test... Not quite. Messing with the elements of `@_` will. Adding elements and removing elements (including assigning to `@_` specifically) won't. `foo($x, $y+1, $z);` [download] is basically equivalent to `{ local @_; alias $_[0] = $x; alias $_[1] = $y+1; alias $_[2] = $z; &foo; }` [download] Changing `$_[0]` in `foo` will change `$x`, for example.	[reply] [d/l] [select]