---
name: "Perl::Critic::Policy::Community::Each"
section: "3pm"
platform: "linux"
package: "libperl-critic-community-perl"
version: "1.0.4-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Perl::Critic::Policy::Community::Each"
---

# Perl::Critic::Policy::Community::Each(3pm)

Don't use each to iterate through a hash

## NAME

Perl::Critic::Policy::Community::Each - Don't use each to iterate through a hash

## DESCRIPTION

The `each()` function relies on an iterator internal to a hash (or array), which is the same iterator used by `keys()` and `values()`. So deleting or adding hash elements during iteration, or just calling `keys()` or `values()` on the hash, will cause undefined behavior and the code will likely break. This could occur even by passing the hash to other functions which operate on the hash. Instead, use a `"foreach"` loop iterating through the keys or values of the hash.

```
  while (my ($key, $value) = each %hash) { ... }                # not ok
  foreach my $key (keys %hash) { my $value = $hash{$key}; ... } # ok
  foreach my $i (0..$#array) { my $elem = $array[$i]; ... }     # ok
```

## AFFILIATION

This policy is part of Perl::Critic::Community.

## CONFIGURATION

This policy is not configurable except for the standard options.

## AUTHOR

Dan Book, `"dbook@cpan.org"`

## COPYRIGHT AND LICENSE

Copyright 2015, Dan Book.

This library is free software; you may redistribute it and/or modify it under the terms of the Artistic License version 2.0.

## SEE ALSO

Perl::Critic, \<http://blogs.perl.org/users/rurban/2014/04/do-not-use-each.html\>