The stupid question is the question not asked | |
PerlMonks |
comment on |
( [id://3333]=superdoc: print w/replies, xml ) | Need Help?? |
It works because of the way the while loop works: The conditional in the while loop always gets evaluated first, before the content of the loop block. The <A> operator, when used in a while conditional, assigns the line gotten from file A to $_, starting with the 1st line. The body of the loop, again uses the <A> operator, which gets the next line; you can access a line only once using the <> operator. I use it directly as the key to the %pairs hash, so the key is the 2nd line. It assigns the value of $_ (which was set in the while conditional) to this element of %pairs. The loop evaluates the conditional again, gets the 3rd line, and assigns it to $_, and the body does the same all over again with the fourth line. So the even/odd mechanism is caused by the double use of <A>. If I wanted to key on the odd lines, I'd've used $pairs{$_}=<A>; In reply to Re^3: Insert row from file
by Gilimanjaro
|
|