In this course, you will run through a comprehensive overview of the YAML data serialization language and its syntax. You will also cover the basic concepts behind this language, understand its main features, and the capabilities of YAML. 

You will kick things off by understanding what exactly YAML is. You will then move on to more concrete topics like syntax, data types, and more complex data types such as sequences, mappings, and pairs.

By the end of this course, you will have a great new skill that is transferable and highly applicable.

Tarun Telang

Tarun Telang is a passionate software engineer, blogger, author and active contributor in online technical forums like DZone and SAP Developer Community Network.

DevOps Expert

Introduction to YAML

## Sequence (`!!seq`)

**Sequence** represents a collection indexed by sequential integers starting with zero as `[0..n-1]`, where `n` is the number of items in the sequence.

It is specified by placing each member on a new line with a _hyphen or dash character_ (`-`). See its usage in the example below.

**Example**
```yaml
- red
- orange
- yellow
```
or 

**Example**
```yaml
# Ordered sequence of nodes
colors: !!seq
  - red
  - orange
  - yellow
```

There is also a compact notation using `[]` for sequence. The above sequence can also be represented as the example below: 

**Example**
```yaml
[red, orange, yellow]
```

The following is a graphical representation of the sequence in the code example:

# Sequence (`!!seq`)

**Sequence** represents a collection indexed by sequential integers starting with zero as `[0..n-1]`, where `n` is the number of items in the sequence.

It is specified by placing each member on a new line with a _hyphen or dash character_ (`-`). See its usage in the example below.

**Example**
```yaml
- red
- orange
- yellow
```
or 

**Example**
```yaml
# Ordered sequence of nodes
colors: !!seq
  - red
  - orange
  - yellow
```

There is also a compact notation using `[]` for sequence. The above sequence can also be represented as the example below: 

**Example**
```yaml
[red, orange, yellow]
```

The following is a graphical representation of the sequence in the code example:

Learn the advanced data types and how to represent them in YAML.

YAML overview

Syntax of YAML

Applications of YAML

Course assessment

Overview of advanced data types in YAML

Sequence (`!!seq`)