caption: fields
created: 20140924115616653
modified: 20200129165038748
op-input: a [[selection of titles|Title Selection]]
op-output: all the field names contained in the input tiddlers
op-parameter: <<.from-version "5.1.22">> optional: a [[list of field names|TiddlerFields]]
op-purpose: select all field names of the input titles
op-suffix: <<.from-version "5.1.22">> optional: `include`, `exclude` parameter list
tags: [[Filter Operators]] [[Field Operators]]
title: fields Operator
type: text/vnd.tiddlywiki

Each input title is processed in turn. Its list of field names is retrieved (in no particular order) and then [[dominantly appended|Dominant Append]] to the operator's output. 

<<.from-version "5.1.22">> If the `include` suffix is used, fields are only included, if they exist. It doesn't matter, if fields have a value. The `exclude` suffix is there for convenience, since it would be possible to use a second filter run. For more info see the examples.

<<.operator-examples "fields">>