1
Which one of the following is a major difference between the chop and chomp functions?
chomp and chop
Chomp cuts off only the current input record separator value; chop cuts off any character.
for example:
$a="abcde";
chomp($a);
chop($a);-------abcd
2 reverse
reverse 函数
例子：
print reverse <<EOF
hello WoRLD
This is teXt
EOF
结果：
DLEoW oLleh
tXet si sihT
this is tricky. Because scalar(reverse())
scalar ask reverse to be in scalar context. So reverse will reverse everything!!!
In list context,returns a list value consisting of the elements of LIST in the opposite order.
In scalar context,concatenates the elements of LIST and returns a string value with all characters in the opposite order.
print join(",",reverse "world","Hello"); # Hello,world?
print scalar reverse "dlrow,"olleH"; # Hello,world
First is List context. The second is scalar context.
It also interesting when you reverse a hash.
my %a = reverse %b;
See what happened?
the key->value changed to value->key.
If same value exists,only one of them kept.
my %a=('a'=>1,'b'=>2); my %b = reverse %a; foreach my $key(keys %b){ ? print "$key -> $b{$key}n"; }
