yq/pkg/yqlib/doc/operators/headers/multiply-merge.md

# Multiply (Merge)

Like the multiple operator in jq, depending on the operands, this multiply operator will do different things. Currently numbers, arrays and objects are supported.

## Objects and arrays - merging
Objects are merged deeply matching on matching keys. By default, array values override and are not deeply merged.

Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.

### Merge Flags
You can control how objects are merged by using one or more of the following flags. Multiple flags can be used together, e.g. `.a *+? .b`.  See examples below

- `+` to append arrays
- `?` to only merge existing fields
- `d` to deeply merge arrays

### Merging files
Note the use of `eval-all` to ensure all documents are loaded into memory.

```bash
yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml
```
Update document generation script 2021-11-03 04:00:58 +00:00			`# Multiply (Merge)`

Arrays no longer deeply merge by defauly, like jq 2021-02-18 00:16:54 +00:00			`Like the multiple operator in jq, depending on the operands, this multiply operator will do different things. Currently numbers, arrays and objects are supported.`
include docs for tracking 2020-11-17 22:44:16 +00:00
Arrays no longer deeply merge by defauly, like jq 2021-02-18 00:16:54 +00:00			`## Objects and arrays - merging`
			`Objects are merged deeply matching on matching keys. By default, array values override and are not deeply merged.`
Added append equals, merge append. Fixed creating numeric arrays 2020-11-28 00:24:16 +00:00
Fixing docs 2020-11-22 02:16:54 +00:00			`Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below.`

Arrays no longer deeply merge by defauly, like jq 2021-02-18 00:16:54 +00:00			`### Merge Flags`
			You can control how objects are merged by using one or more of the following flags. Multiple flags can be used together, e.g. `.a *+? .b`. See examples below
Fixing multiply doc 2021-01-14 09:28:57 +00:00
Arrays no longer deeply merge by defauly, like jq 2021-02-18 00:16:54 +00:00			- `+` to append arrays
			- `?` to only merge existing fields
			- `d` to deeply merge arrays

			`### Merging files`
Fixing multiply doc 2021-01-14 09:28:57 +00:00			Note the use of `eval-all` to ensure all documents are loaded into memory.
Fixing docs 2020-11-22 02:16:54 +00:00
			```bash
			`yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml`
			```