QGIS/resources/function_help/json/concat

{
  "name": "concat",
  "type": "function",
  "groups": ["String"],
  "description": "Concatenates several strings to one. NULL values are converted to empty strings. Other values (like numbers) are converted to strings.",
  "variableLenArguments": true,
  "arguments": [ {"arg":"string1", "syntaxOnly": true},
                 {"arg":"string2", "syntaxOnly": true},
                 {"arg":"string", "descOnly": true, "description":"a string value"}],
  "examples": [ { "expression":"concat('sun', 'set')", "returns":"'sunset'"},
                { "expression":"concat('a','b','c','d','e')", "returns":"'abcde'"},
                { "expression":"concat('Anno ', 1984)", "returns":"'Anno 1984'"},
                { "expression":"concat('The Wall', NULL)", "returns":"'The Wall'"}]
}