Learn basic concepts, key features, and capabilities of YAML.

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

# Data types in YAML

YAML supports most of the data types of agile programming languages such as Perl, Python, PHP, Java, C#, Ruby, and JavaScript.  

The following is the list of supported data types:
- Boolean
- Numbers 
- Strings
- Dates
- Timestamp
- Arrays 
- Maps 
- Null 

## Variable (Scalars)

A name followed by a colon (`:`) and a single space (` `) defines a **variable**. Variables can also be referred to as **scalars**. 

See the example below about how to represent variables in YAML.

**Example** 
```yaml
string: "Hello"
integer: 123
float: 12.345
boolean: No
```
Below is the graphical representation of the example above: 


@startyaml
<style>
yamlDiagram {
  node {
    FontSize 36
  }
}
</style>
string: "Hello"
integer: 123
float: 12.345
boolean: No 
@endyaml




### String variable 

Strings can be written **without** quotes or enclosed within a pair of `'` single or `"` double quotation symbols. 

**Example**
```yaml 
name: !!str "James"
message: !!str "This is a \n multiline text"
```

Below is the example to demonstrate the different ways of representing Strings in 'YAML'.

**Example** 
```yaml
text: Hello
quoted: 
  - 'single quoted string'
  - "double quoted strings"
```

Below is the graphical representation of the above example: 

@startyaml
<style>
yamlDiagram {
  node {
    FontSize 36
  }
}
</style>
text: Hello
quoted: 
  - 'single quoted string'
  - " double quoted strings"
@endyaml


Note:  

A `|` character denotes **a string with newlines, indentations and spaces preserved**. This is also referred to as **pipe notation** in YAML. See its usage in the example below.

**Example** 
```yaml
text: | 
  Every line in this text 
  will be stored 
  as separate lines.
```

A `>` character denotes **a string with newlines folded**. This is also referred to as **newlines folded notation**. See its usage in the example below.


In this lesson, you would learn about various data types in YAML and their usage. 

YAML overview

Syntax of YAML

Applications of YAML

Course assessment

Overview of data types in YAML