> For the complete documentation index, see [llms.txt](https://mikefarah.gitbook.io/yq/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mikefarah.gitbook.io/yq/operators/first.md).

# First Operator

Returns the first matching element in an array, or first matching value in a map.

Can be given an expression to match with, otherwise will just return the first.

## First matching element from array

Given a sample.yml file of:

```yaml
- a: banana
- a: cat
- a: apple
```

then

```bash
yq 'first(.a == "cat")' sample.yml
```

will output

```yaml
a: cat
```

## First matching element from array with multiple matches

Given a sample.yml file of:

```yaml
- a: banana
- a: cat
  b: firstCat
- a: apple
- a: cat
  b: secondCat
```

then

```bash
yq 'first(.a == "cat")' sample.yml
```

will output

```yaml
a: cat
b: firstCat
```

## First matching element from array with numeric condition

Given a sample.yml file of:

```yaml
- a: 10
- a: 100
- a: 1
- a: 101
```

then

```bash
yq 'first(.a > 50)' sample.yml
```

will output

```yaml
a: 100
```

## First matching element from array with boolean condition

Given a sample.yml file of:

```yaml
- a: false
- a: true
  b: firstTrue
- a: false
- a: true
  b: secondTrue
```

then

```bash
yq 'first(.a == true)' sample.yml
```

will output

```yaml
a: true
b: firstTrue
```

## First matching element from array with null values

Given a sample.yml file of:

```yaml
- a: null
- a: cat
- a: apple
```

then

```bash
yq 'first(.a != null)' sample.yml
```

will output

```yaml
a: cat
```

## First matching element from array with complex condition

Given a sample.yml file of:

```yaml
- a: dog
  b: 7
- a: cat
  b: 3
- a: apple
  b: 5
```

then

```bash
yq 'first(.b > 4 and .b < 6)' sample.yml
```

will output

```yaml
a: apple
b: 5
```

## First matching element from map

Given a sample.yml file of:

```yaml
x:
  a: banana
y:
  a: cat
z:
  a: apple
```

then

```bash
yq 'first(.a == "cat")' sample.yml
```

will output

```yaml
a: cat
```

## First matching element from map with numeric condition

Given a sample.yml file of:

```yaml
x:
  a: 10
y:
  a: 100
z:
  a: 101
```

then

```bash
yq 'first(.a > 50)' sample.yml
```

will output

```yaml
a: 100
```

## First matching element from nested structure

Given a sample.yml file of:

```yaml
items:
  - a: banana
  - a: cat
  - a: apple
```

then

```bash
yq '.items | first(.a == "cat")' sample.yml
```

will output

```yaml
a: cat
```

## First matching element with no matches

Given a sample.yml file of:

```yaml
- a: banana
- a: cat
- a: apple
```

then

```bash
yq 'first(.a == "dog")' sample.yml
```

will output

```yaml
```

## First matching element from empty array

Given a sample.yml file of:

```yaml
[]
```

then

```bash
yq 'first(.a == "cat")' sample.yml
```

will output

```yaml
```

## First matching element from scalar node

Given a sample.yml file of:

```yaml
hello
```

then

```bash
yq 'first(. == "hello")' sample.yml
```

will output

```yaml
```

## First matching element from null node

Given a sample.yml file of:

```yaml
null
```

then

```bash
yq 'first(. == "hello")' sample.yml
```

will output

```yaml
```

## First matching element with string condition

Given a sample.yml file of:

```yaml
- a: banana
- a: cat
- a: apple
```

then

```bash
yq 'first(.a | test("^c"))' sample.yml
```

will output

```yaml
a: cat
```

## First matching element with length condition

Given a sample.yml file of:

```yaml
- a: hi
- a: hello
- a: world
```

then

```bash
yq 'first(.a | length > 4)' sample.yml
```

will output

```yaml
a: hello
```

## First matching element from array of strings

Given a sample.yml file of:

```yaml
- banana
- cat
- apple
```

then

```bash
yq 'first(. == "cat")' sample.yml
```

will output

```yaml
cat
```

## First matching element from array of numbers

Given a sample.yml file of:

```yaml
- 10
- 100
- 1
```

then

```bash
yq 'first(. > 50)' sample.yml
```

will output

```yaml
100
```

## First element with no filter from array

Given a sample.yml file of:

```yaml
- 10
- 100
- 1
```

then

```bash
yq 'first' sample.yml
```

will output

```yaml
10
```

## First element with no filter from array of maps

Given a sample.yml file of:

```yaml
- a: 10
- a: 100
```

then

```bash
yq 'first' sample.yml
```

will output

```yaml
a: 10
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://mikefarah.gitbook.io/yq/operators/first.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.