QGIS/resources/function_help/json/array_agg

{
  "name": "array_agg",
  "type": "function",
  "groups": ["Aggregates"],
  "description": "Returns an array of aggregated values from a field or expression.",
  "arguments": [
    {"arg": "expression", "description": "sub expression of field to aggregate"},
    {"arg": "group_by", "optional": true, "description": "optional expression to use to group aggregate calculations"},
    {"arg": "filter", "optional": true, "description": "optional expression to use to filter features used to calculate aggregate"},
    {"arg": "order_by", "optional": true, "description": "optional expression to use to order features used to calculate aggregate. By default, the features will be returned in an unspecified order."}
  ],
  "examples": [
    { "expression": "array_agg(\"name\",group_by:=\"state\")", "returns":"list of name values, grouped by state field"}
  ]
}