yaml_Ansible

 YAML Data Types

YAML organizes data using three basic data types: scalars, sequences, and maps. Each of these data types has its own syntax and structure.

1. Scalars

A scalar is a single value, such as a string, number, or boolean. Scalars can be represented in various ways in YAML, including plain style, double-quoted style, and single-quoted style.

name: Alagarasan

age: 30

is_devops_consultant: true

In the above example, name is a string scalar, age is a numeric scalar, and is_devops_consultant is a boolean scalar.

Key value

key: value

key = name

: = Seprator. # Space after colon is mandatory

value = data

String

Text values (quoted or unquoted)

name: Alagarasan

role: "DevOps Engineer"

company: 'TCS'

Integer (Number)

Numeric values without a decimal point (whole numbers)

age: 30

experience: 8

Float (Number)

Numeric values with a decimal point (floating-point numbers)

cpu_usage: 75.5

version: 1.2

Boolean

True or false values

is_active: true

is_admin: false

Null (Empty value)

null is not a string, It represents absence of value

Null (Empty value)

null means:👉 No value / empty value / nothing assigned

~ is a shorthand for null in YAML. It represents the absence of a value, similar to null in other programming languages. When you see ~ in a YAML file, it indicates that the value is intentionally left empty or not assigned.

value1: null

value2: Null

value3: NULL

value4: ~

value5:

eg

user:

name: Alagarasan

middle_name: null

nickname: ~

age: 30

is_active: true

NAN (Not a Number)

NaN stands for: Not a Number. It is a special floating-point value that represents an undefined or unrepresentable value, such as the result of dividing zero by zero.

result: .nan

result: .NaN

result: .NAN

eg

metrics:

cpu_usage: 75.5

memory_usage: .nan

👉 Here:

cpu_usage → valid number

memory_usage → undefined / not measurable

.infinite (INF)

INF stands for: Infinity. It is a special floating-point value that represents an infinitely large number

positive_infinity: .inf

negative_infinity: -.inf

also_positive_infinity: .INF

also_negative_infinity: -.INF

Positive vs Negative Infinity

positive: .inf

negative: -.inf

👉 Meaning:

.inf → +∞

-.inf → −∞