# init(contentsOfJSONFile:columns:types:options:) Creates a data frame by reading a JSON file. ``` init(contentsOfJSONFile url: URL, columns: [String]? = nil, types: [String : JSONType] = [:], options: JSONReadingOptions = .init()) throws ``` ## Parameters `url` A URL to a JSON file. `columns` An array of column names; Set to `nil` to use every column in the JSON file. `types` A dictionary of column names and their JSON types. The data frame infers the types for column names that aren’t in the dictionary. `options` The options that instruct how the data frame reads the JSON file. ## Discussion The JSON file should contain a sequence of objects where each object contains a value for every column name. Here’s an example with two columns “id” and “name”: ``` [ {"id": 1, "name": "foo"}, {"id": 2, "name": "bar"}, ] ``` > Throws: A `JSONReadingError` instance. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)