for iterates over a list, everything in brackets is expanded (the only exception are ranges ). So <> will create a temporary list.

while loops as long a boolean expression is true.

This can be used together with an iterator, like while($x=iter()) .

There is no general automatism to set $_ like your example implies, that's just magic behavior of the file iterator <> in scalar context. that boolean context.

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!

In reply to Re: Internally, how do for() and while() differ? by LanX
in thread Internally, how do for() and while() differ? by stevieb

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