The JavaScript exception "new keyword cannot be used with an optional chain" occurs when the constructor of a new expression is an optional chain, or if there's an optional chain between the constructor and the parenthesized list of arguments.

Prints to the standard error, with a newline.

The JavaScript exception "numbers out of order in {} quantifier" occurs when a quantifier in a regular expression uses the {n,m} syntax but m is less than n.

Parses a file as an expression or an item according to the context.

Asynchronous basic functionality.

{"id":352,"date":"2023-08-25T17:22:34","date_gmt":"2023-08-25T17:22:34","guid":{"rendered":"\/\/api.jquery.com\/?p=352"},"modified":"2025-03-24T16:57:24","modified_gmt":"2025-03-24T16:57:24","slug"...

The JavaScript exception "can't define property "x": "obj" is not extensible" occurs when an object is marked as non-extensible, so that it will never have properties beyond the ones it had at the time it was marked as non-extensible. Objects can be made non-extensible by calling Object.preventExtensions(), Object.seal(), or Object.freeze().

A helper trait used for indexing operations.

{"version":"1.0","provider_name":"jQuery API Documentation","provider_url":"https:\/\/api.jquery.com","author_name":"builder","author_url":"https:\/\/api.jquery.com\/author\/builder\/","title":"Nex...

{"version":"1.0","provider_name":"jQuery API Documentation","provider_url":"https:\/\/api.jquery.com","author_name":"builder","author_url":"https:\/\/api.jquery.com\/author\/builder\/","title":".mo...