Arrow Functions
Explain arrow function syntax and how lexical `this` differs from regular functions.
Short explanation
Arrow functions are a concise syntax for writing functions. They also capture
the this value lexically from the surrounding scope, which makes them
especially useful for callbacks.
Syntax example
const add = (a, b) => a + b;
const obj = {
value: 42,
getValue: () => this.value, // this is lexically inherited — often undefined in this context
};
How JS handles it internally
Arrow functions do not create their own this binding, arguments object, or
prototype. Instead, they use the this from the enclosing scope. Because of
these differences, they are not suitable as constructors.
FAQ
Q: Can arrow functions be used as constructors?
A: No — they do not have a [[Construct]] method and will throw when used with
new.