yq/operators/filter.md

# Filter

Filters an array (or map values) by the expression given. Equivalent to doing `map(select(exp))`.


## Filter array
Given a sample.yml file of:
```yaml
- 1
- 2
- 3
```
then
```bash
yq 'filter(. < 3)' sample.yml
```
will output
```yaml
- 1
- 2
```

## Filter map values
Given a sample.yml file of:
```yaml
c:
  things: cool
  frog: yes
d:
  things: hot
  frog: false
```
then
```bash
yq 'filter(.things == "cool")' sample.yml
```
will output
```yaml
- things: cool
  frog: yes
```