---
name: "Catmandu::Fix::add_field"
section: "3pm"
platform: "linux"
package: "libcatmandu-perl"
version: "1.2024-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Catmandu::Fix::add_field"
---

# Catmandu::Fix::add\_field(3pm)

add or change the value of a HASH key or ARRAY index

## NAME

Catmandu::Fix::add\_field - add or change the value of a HASH key or ARRAY index

## DESCRIPTION

Contrary to `"set_field"`, this will create the intermediate structures if they are missing.

## SYNOPSIS

```
   # Add a new field 'foo' with value 2
   add_field(foo, 2)
   # Change the value of 'foo' to 'bar 123'
   add_field(foo, 'bar 123')
   # Create a deeply nested key
   add_field(my.deep.nested.key, hi)
   # If the second argument is omitted the field has a null value
   add_field(foo)
```

## SEE ALSO

Catmandu::Fix