The JavaScript exception "await is only valid in async functions, async generators and modules" occurs when an await expression is used outside of async functions or modules or other async contexts.

The JavaScript exception "must call super constructor before using 'this' in derived class constructor" occurs when the super() is not called for a given derived class constructor, and the derived constructor tries to access the value of this, or the derived constructor has already returned and the return value is not an object.

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id: 54 count: 2 description: These methods allow us to associate arbitrary data with specific DOM elements. link: https://api.jquery.com/category/miscellaneous/data-storage/ name: Data Storage slug...

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A named backreference refers to the submatch of a previous named capturing group and matches the same text as that group. For unnamed capturing groups, you need to use the normal backreference syntax.

The JavaScript exception "parameter after rest parameter" occurs when a rest parameter is followed by anything else in a parameter list, including another rest parameter, a formal parameter, or a trailing comma.

id: 108 date: 2023-08-25T17:22:20 date_gmt: 2023-08-25T17:22:20 guid.rendered: //api.jquery.com/?p=108 modified: 2026-01-20T17:34:20 modified_gmt: 2026-01-20T17:34:20 slug: child-selector status: p...

The function declaration creates a binding of a new function to a given name.