How to do jq arithmetic under Windows-CodePudding

I am reading the jq manual and it says, that and - operations on number should "just work". However, I can't seem to be able to use them in almost any operation, for example, in object construction

Given input.json as {"a": 4}

this command:

jq "6-.a" input.json

produces

but this command:

jq "{b: 6-.a}" input.json

produces

jq: error: syntax error, unexpected '-', expecting '}' (Windows cmd shell quoting issues?) at <top-level>, line 1:
{b: 6-.a}     
jq: 1 compile error

How to work this around? Thanks

CodePudding user response：

When constructing objects with expressions as key or value, the expression needs to be surrounded by parentheses:

jq "{b: (6-.a)}" input.json

{
  "b": 2
}

Demo