QGIS/resources/function_help/json/map_insert

{
  "name": "map_insert",
  "type": "function",
  "groups": ["Maps"],
  "description": "Returns a map with an added key/value.",
  "arguments": [ {"arg":"map","description":"a map"},
                 {"arg":"key","description":"the key to add"},
                 {"arg":"value","description":"the value to add"}],
  "examples": [ { "expression":"map_insert(map('1','one'),'3','three')", "returns":"{ '1': 'one', '3': 'three' }"}]
}