2.1. Hash-Related Functions
delete
delete can be used to remove a key or a set of keys out of a hash. For example:
$myhash{"hello"} = "world"; $myhash{"perl"} = "TMTOWTDI"; $myhash{"shlomi"} = "fish"; if (exists($myhash{"perl"})) { print "The key perl exists!\n"; } else { print "The key perl does not exist!\n"; } delete($myhash{"perl"}); if (exists($myhash{"perl"})) { print "The key perl exists!\n"; } else { print "The key perl does not exist!\n"; }
The Comma Regarding Hashes
The comma can be used to combine two arrays into one larger one. Given the fact that a mini-hash with one key and one value can be specified using the $key => $value notation (which is essentially equivalent to $key, $value) a hash can be initialized in one statement.
Here's an example:
%hash1 = ( "shlomi" => "fish", "orr" => "dunkelman", "guy" => "keren" ); %hash2 = ( "george" => "washington", "jules" => "verne", "isaac" => "newton" ); %combined = (%hash1, %hash2); foreach $key (keys(%combined)) { print $key, " = ", $combined{$key}, "\n"; }
If the two combined hashes contain several identical keys, then the values of the latter hash will win.