my $foo = "a string";
print "\$foo is $foo\n";

## this $foo only lasts to the end of the for loop scope
for my $foo (1..3) {
    print "\$foo is $foo\n";
}

print "\$foo is $foo\n";

__output__

$foo is a string
$foo is 1
$foo is 2
$foo is 3
$foo is a string