Resource Orchestration Service:Fn::Calculate

Declaration

• JSON

  {
    "Fn::Calculate": [
      "expression",
      ndigits,
      [
        <number1>,
        <number2>,
        ...
      ]
    ]
  }

• YAML

  • Syntax for the full function name:

    Fn::Calculate:
      - expression
      - ndigits
      - - <number1>
        - <number2>
        - ...

  • Syntax for the short form:

    !Calculate 
    	- expression
      - ndigits
      - - <number1>
        - <number2>
        - ...

Parameters

• expression: an expression of the String type.

• ndigits: the number of decimal places in the result. The value must be 0 or a positive integer. This parameter takes effect only when the expression contains floating-point numbers.

• [<number0>, <number1>, <number2>, ... ]: optional. You can define {n} in the expression, where n is the index of a number. During calculation, {n} is replaced with the corresponding number.

Return value

The calculation result of the expression, returned as a Number.

Examples

!Calculate
  - (2+3)/2*3-1
  - 1
!Calculate
  - (2.0+3)/2*3-1
  - 1
!Calculate
  - ({1}+3)/2*3-1
  - 1
  - - 3
    - 5
    - 6
!Calculate
  - ({0}+{1})%3
  - 0
  - - 5
    - 6

5 
6.5
11
2