Frank <mailto:[EMAIL PROTECTED]> wrote:
: The results given like this, it seems the loop works only for one time
:
: >common_white
: paper
: >milk_white
: milk
This is what you asked perl to do. Let's walk the script.
First time through $item is ">blue". Since $after_white tests false,
this is what happens (nothing).
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
}
}
Next time through $item is "sky". Since $after_white tests false,
this is what happens (nothing).
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
}
}
Next time through $item is "skirt". Since $after_white tests false,
this is what happens (nothing).
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
}
}
Next time through $item is "sea". Since $after_white tests false,
this is what happens (nothing).
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
}
}
Next time through $item is ">common_white". Since both
$after_white and "$item =~ /^>/" test true, this is what
happens.
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
print "$item\n";
next if $item =~ /^>/;
}
}
Next time through $item is "paper". Since $after_white tests true,
but "$item =~ /^>/" tests false, this is what happens. Note that
$after_white will test false after this.
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
print "$item\n";
next if $item =~ /^>/;
$after_white = undef;
}
}
Next time through $item is "flower". Since $after_white tests
false, this is what happens (nothing).
foreach my $item ( @items ) {
$after_white = 1 if $item =~ /white$/;
if ( $after_white ) {
}
}
Do you see the error now? You told perl to stop after the second
line was printed. You didn't give a stopping point like you did last
time.
You need a small ego to be a computer programmer. You are very
unlikely to run into a perl bug. Assume every problem you have as
your own fault. This often means stepping through a script one line
at a time to find your error.
HTH,
Charles K. Clarkson
--
Mobile Homes Specialist
254 968-8328
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