This is a minor thing, that I bet all the senior monks know, but I only just found it out, and it was very useful, so maybe newbies like me might be interested.

I was doing something where I needed to have two different increments happening in my "for" loop.

I was doing it like this, because I didn't know any better: 

$j=0;

for( $i=0; $i<20 ; $i++){
  print "\$i = $i and \$j = $j";
  $j++
}

[download]

but then someone pointed out to me that I could have more than one thing in the three arguments to "for", separated with commas: 

for( $i=0,$j=0; $i<20,$j<20 ; $i++,$j++){
  print "\$i = $i and \$j = $j";
}

[download]

and not only that but I found that "and" and "or" statements worked too: 

for( $i=0,$j=0; $i<20 or $j<20 ; $i++,$j++){
  print "\$i = $i and \$j = $j";
}

[download]
for( $i=0,$j=0; $i<20 and $j<20 ; $i++,$j++){
  print "\$i = $i and \$j = $j";
}

[download]

OK, just so I can make this into a question, I look up "for" and of course it says "for (EXPR; EXPR; EXPR)", but where's my clue that my EXPR can be a set of statements separated by commas?

I obviously can't separate them with semicolons, but how was I supposed to figure out that commas were the answer?

--
Weaselling out of things is important. It's what separates us from the animals ... except the weasel.

In reply to Newbie realisation about by Cody Pendant

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