QGIS/resources/function_help/json/map_exist

{
  "name": "map_exist",
  "type": "function",
  "groups": ["Maps"],
  "description": "Returns TRUE if the given key exists in the map.",
  "arguments": [{
    "arg": "map",
    "description": "a map"
  }, {
    "arg": "key",
    "description": "the key to lookup"
  }],
  "examples": [{
    "expression": "map_exist(map('1','one','2','two'),'3')",
    "returns": "FALSE"
  }],
  "tags": ["map", "exists", "key"]
}