AWS CloudFormation Concepts Intrinsic Functions

External

Intrinsic Function Reference

Internal

• AWS CloudFormation Concepts

Ref

Ref

The intrinsic function Ref returns the value of the specified parameter or resource. When a parameter logical name is specified, it returns the value of the parameter. When a resource logical name is specified, it returns a value that can be typically used to refer to that resource, such as a physical ID.

Join

Join

!Join [ delimiter, [ comma-delimited list of values ] ]

!Join ['-', [ a, b, c ]]

returns "a:b:c"

Split

Split

!Split ['.', "www.example.com"]

returns ["www", "example", "com"].

Select

Select

Sub

Sub

If only template parameters, resource logical IDs and resource attributes are substituted in the String parameter, no variable map is required:

!Sub '${AWS::Region}-something'