Do Arrow Functions Have Their Own Arguments Object in ES6?

ES6 Arrow Functions: The Enigma of arguments

In the realm of JavaScript, arrow functions have emerged as a concise and elegant alternative to traditional function declarations. However, the treatment of the arguments object within arrow functions has sparked controversy, leading to conflicting behavior across different platforms.

Initial recommendations from the TC39 committee suggested that arrow functions should not have their own arguments binding, relying instead on the arguments object of the parent scope. However, some browsers (Chrome, Firefox, Node) seem to contradict this notion, allowing arrow functions to access the arguments object of their enclosing scope.

To clarify this ambiguity, let's delve into the official documentation:

• ES6 Specification, Section 14.2.11.1: "Arrow function expressions evaluate to functions that have their [[ThisMode]] set to lexical." This implies that arrow functions inherit the lexical environment of their parent scope.
• ES6 Specification, Section 18: "(18 a) Arrow functions never have an arguments objects." This statement explicitly confirms that arrow functions do not have their own arguments object.

Based on these official documents, it is clear that the behavior observed in Chrome, Firefox, and Node is erroneous. Arrow functions are not intended to have an arguments binding, and relying on this behavior can lead to unreliable and confusing code.

Therefore, developers should adhere to the intended semantics of arrow functions and avoid relying on the presence of an arguments object within their scope. This will ensure consistent and predictable behavior across all JavaScript platforms.

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