Salesforce JavaScript Developer Practice Exam

In which scenario will an arrow function not bind its own `this`?

1. When used as a method in an object.

2. When used in a regular function.

3. When used in a callback.

4. When used within a class.

The correct answer is: When used in a callback.

An arrow function does not bind its own `this` context, which means it inherits `this` from the parent scope in which it is defined. This is particularly useful in scenarios where you want to maintain the context of `this` from an outer function. When an arrow function is used as a callback, it retains the `this` value from the enclosing lexical context, which is why the chosen answer is accurate. For example, if an arrow function is defined inside a method of an object, and that method is called as a callback for an event, the `this` inside the arrow function will refer to the object the method belongs to, rather than the global object or undefined (as would happen in a non-arrow function). In contrast, when used as a method in an object, an arrow function will not behave as a traditional method because it will not create its own context for `this`. Similarly, when used in a regular function, `this` will depend on how that function is called, leading to potentially unexpected behavior. Within a class, though arrow functions can be used to define methods, they will still not have their own `this`, and will inherit it from the context in which they are defined. Thus, the inherent