perl hash operations

Perl is a programming language that provides built-in support for hash data structures. Hashes in Perl are unordered collections of key-value pairs.

To create a hash, you can use the % symbol followed by a variable name. For example:

my %hash;

To add elements to the hash, you can use the assignment operator (=) along with curly braces ({}). Each key-value pair is separated by a comma. Here's an example:

%hash = (
    "key1" => "value1",
    "key2" => "value2",
    "key3" => "value3"

To access the value associated with a specific key, you can use the key inside square brackets ([]) after the hash variable. Here's an example:

my $value = $hash{"key1"};

To change the value associated with a key, you can simply assign a new value to it. For example:

$hash{"key2"} = "new value";

To delete a key-value pair from the hash, you can use the delete function. Here's an example:

delete $hash{"key3"};

You can also check if a key exists in a hash using the exists function. It returns true if the key exists and false otherwise. Here's an example:

if (exists $hash{"key1"}) {
    # Key exists in the hash
} else {
    # Key does not exist in the hash

Iterating over a hash can be done using the foreach loop. Here's an example:

foreach my $key (keys %hash) {
    my $value = $hash{$key};
    # Do something with the key and value

These are some basic operations you can perform on hashes in Perl. Hashes are a versatile data structure that can be used for various purposes in Perl programming.