The Perl Toolchain Summit 2025 Needs You: You can help 🙏 Learn more

NAME

Deep::Hash::Exists - Verify existence of keys hash.

SYNOPSIS

use Deep::Hash::Exists ':all';
my $hash_ref = {
A => 'one',
B => [ 'one', 'two' ],
C => {
'one' => 1,
'two' => 2,
},
};
key_exists( $hash_ref, [ 'C', 'one' ] ); # return 1
key_exists( $hash_ref, [ 'D' ] ); # return 0
every_keys( $hash_ref, [ ['A'], ['B', 0], ['C', 'one'] ] ); # return 0
every_keys( $hash_ref, [ ['A'], ['B'], ['C', 'one'] ] ); # return 1
some_keys( $hash_ref, [ ['A'], ['B', 0], ['C', 'one'] ] ); # return 1
some_keys( $hash_ref, [ ['D'], ['B', 0], ['C', 'six'] ] ); # return 0

DESCRIPTION

Exists hash:

my $hash_ref = {
A => 'one',
B => [ 'one', 'two' ],
C => {
'one' => 1,
'two' => 2,
},
};

If verify existence of keys standard way, will be created non existent keys:

exists $hash_ref->{C}{three}{PI}{0};
print Dumper $hash_ref;

Output:

# $VAR1 = {
# 'A' => 'one',
# 'B' => [
# 'one',
# 'two'
# ]
# 'C' => {
# 'one' => 1,
# 'two' => 2,
# 'three' => {
# 'PI' => {}
# }
# },
# };

Subroutine key_exists does not create new keys:

key_exists( $hash_ref, [ 'C', 'three', 'PI', 0 ] );
print Dumper $hash_ref;

Output:

# $VAR1 = {
# 'A' => 'one',
# 'B' => [
# 'one',
# 'two'
# ],
# 'C' => {
# 'one' => 1,
# 'two' => 2
# }
# };

METHODS

The first argument in methods key_exists, every_keys and some_keys can be a hash reference and a blessed hash.

key_exists($$)

key_exists( $hash_ref, $array_ref_keys ) - Verify existence of keys hash.

Return:

If exist keys of hash then return 1, otherwise - 0.

Example:

my $hash_ref = {
A => 'one',
B => [ 'one', 'two' ],
C => {
'one' => 1,
'two' => 2,
},
};
printf "Output: %s", key_exists( $hash_ref, [ 'A' ] );
# Output: 1
printf "Output: %s", key_exists( $hash_ref, [ 'B' ] );
# Output: 1
printf "Output: %s", key_exists( $hash_ref, [ 'B', 0 ] );
# Output: 0
printf "Output: %s", key_exists( $hash_ref, [ 'C', 'one' ] );
# Output: 1
printf "Output: %s", key_exists( $hash_ref, [ 'C', 'three' ] );
# Output: 0
printf "Output: %s", key_exists( $hash_ref, [ 'C', 'three', 'PI', 0 ] );
# Output: 0
# Subroutine does not create new keys.

every_keys($$)

every_keys( $hash_ref, $list_array_ref ) - Verify list of hash keys for existence.

Return:

If exist all keys of hash of the submitted list then return 1, otherwise - 0.

Example:

my $hash_ref = {
A => 'one',
B => [ 'one', 'two' ],
C => {
'one' => 1,
'two' => 2,
},
};
printf "Output: %s", every_keys( $hash_ref, [ ['A'], ['B', 0], ['C', 'one'] ] );
# Output: 0
printf "Output: %s", every_keys( $hash_ref, [ ['A'], ['C', 'one'], ['C', 'two'] ] );
# Output: 1

some_keys($$)

some_keys( $hash_ref, $list_array_ref ) - Verify list of hash keys for existence.

Return:

If exist at least one key of hash of the submitted list then return 1, otherwise - 0.

Example:

my $hash_ref = {
A => 'one',
B => [ 'one', 'two' ],
C => {
'one' => 1,
'two' => 2,
},
};
printf "Output: %s", some_keys( $hash_ref, [ ['A'], ['B', 0], ['C', 'one'] ] );
# Output: 1
printf "Output: %s", some_keys( $hash_ref, [ ['A', 'one'], ['B', 0], ['C', 'three'] ] );
# Output: 0

SEE ALSO

Hash::Util, Deep::Hash::Utils

COPYRIGHT AND LICENSE

Copyright (C) 2015 Vitaly Simul <vitalysimul@gmail.com>

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

AUTHOR

Vitaly Simul <vitalysimul@gmail.com>