Closures

Question 1

What must the return value of myFunction be if the following expression is possible?
myFunction( )( );

Answer 1

the return value of the return value

Question 2

In JavaScript, when is a function’s scope determined; when it is called or when it is defined?

Answer 2

when it is defined

Question 3

What allows JavaScript functions to “remember” values from their surroundings?

Answer 3

closures are created every time a function is created - they allow functions to maintain a reference to their lexical environment, containing any local variables that were in-scope at function creation time

Question 4

What does this code do?
const wrap = value => ( ) => value;

Answer 4

defining an anonymous arrow function named wrap that takes one parameter (value) and returns an anonymous arrow function that returns value