#!/usr/bin/env perl -w

#What's wrong here?

#Assume some piece of code has filled @array with many
#(but an unknown number) of integers. We want to
#compute the average of all positive numbers, and stop
#when a number equals -999.  Assume there is at least one
#positive integer before -999.

#<code that fills array here> 

for $num (@array){
    if ($num < 0){
	if ($num == -999){
	    last;
	} else {
	    redo;
	}
    } else {
	$sum+=$num;
	$count++;
    }
}
$avg = $sum/$count;
print "The average of positive integers before -999 is " .$avg."\n";

#---------------------------------------------------------------------------------
#!/usr/bin/env perl -w
use strict;

my %numbers;
my (@small, @big);
my $num;

foreach (1..10){
    $numbers{$_} = $_ * 10;
}

@small = keys %numbers;
@big = values %numbers;

for $num (@small){
    print "$num  ";
}
print "\n";
for (my $i = 0; $i< @big; $i++){
    print "$big[$i] ";
}
print "\n";

#-----------------------------------------------------------------
#!/usr/bin/env perl -w

$i = 0;
do { $i++ } while ($i>0 && $i<5);
print "\$i = $i\n";

$j = 0;
$j++ while ($j>0 && $j<5);
print "\$j = $j\n";

#----------------------------------------------------------
#!/usr/bin/env perl -w

#what's wrong with this code?

#This program is supposed to print the position of each space character
#within the string.  It doesn't work.  Why not?

$string = "This is a string seperated by spaces\n";

$i = 0;
while ($i != -1){
    $i = index $string, " ", $i;
    print "A space was found at position $i\n"; unless $i == -1;
}
#-----------------------------------------------------------------