perl 取出多个hash的值，可以用循环：

下面的代码是遍历hash：

while(($key, $value) = each(%HASH)) {
    # do something with $key and $value
}
#-----------------------------
foreach $key (keys %HASH) {
    $value = $HASH{$key};
    # do something with $key and $value
}
#-----------------------------
# %food_color per the introduction
while(($food, $color) = each(%food_color)) {
    print "$food is $color.\n";
}
# Banana is yellow.
#
# Apple is red.
#
# Carrot is orange.
#
# Lemon is yellow.
 


foreach $food (keys %food_color) {
    my $color = $food_color{$food};
    print "$food is $color.\n";
}