AI solution for JavaScript Quiz on BFE.dev
6. Arrow Function

The code outputs the following:

bfe
bfe
undefined
bfe
bfe
bfe
undefined
undefined
bfe

Explanation:

• obj.a(): returns "bfe" because this inside the function refers to the obj object, and this.dev is "bfe".
• obj.b(): also returns "bfe" for the same reason as above, but using the shorthand method definition syntax.
• obj.c(): returns undefined because arrow function does not have its own this, it just simply captures this from its surrounding context, in this case the global object (or undefined in strict mode). Therefore, this.dev is undefined.
• obj.d(): returns "bfe" because the function d returns the result of an immediately invoked arrow function, which does not have its own this, but is instead taking it from its lexical scope (which is d), where this is referring to the obj object that d is a method of.
• obj.e(): also returns "bfe" because this.b() is essentially equivalent to this.obj.b(), so this inside e refers to obj, which has the b method that returns "bfe".
• obj.f()(): returns "bfe" because calling f returns the b method, and then calling that method returns "bfe".
• obj.g(): returns undefined for the same reason as obj.c().
• obj.h()(): returns undefined because calling h returns the c arrow function, and then calling that arrow function results in capturing this from its surrounding context, which is the global object (or undefined in strict mode).
• obj.i()(): returns "bfe" because calling i returns an arrow function that captures this from its surrounding context, which is obj where this.dev is "bfe".