QGIS/resources/function_help/json/op_plus

{
  "name": "+",
  "type": "operator",
  "groups": ["Operators"],
  "description": "Addition of two values. If one of the values is NULL the result will be NULL.",
  "arguments": [{
    "arg": "a",
    "description": "value"
  }, {
    "arg": "b",
    "description": "value"
  }],
  "examples": [{
    "expression": "5 + 4",
    "returns": "9"
  }, {
    "expression": "5 + NULL",
    "returns": "NULL"
  }, {
    "expression": "'QGIS ' + 'ROCKS'",
    "returns": "'QGIS ROCKS'"
  }, {
    "expression": "to_datetime('2020-08-01 12:00:00') + '1 day 2 hours'",
    "returns": "2020-08-02T14:00:00"
  }],
  "tags": ["addition", "null", "result", "values"]
}