JavaScript

Question 1

How are arrays in JavaScript different to arrays in Java?

Answer 1

Arrays in JavaScript are like a Hash Table in memory

Question 2

if you have an array [1,2,3] could you do a[5] = 20

Answer 2

Yes it would be [1,2,3, <space>, 20]</space>

If you tried to do this in Java you would get an array out of bounds index

Question 3

How do you add and remove elements from an array in JavaScript?

Answer 3

push(value) adds an element
pop() removes the last element

Question 4

In JavaScript, functions are first class citizens what does that mean?

Answer 4

1. Can assign functions to variables
2. Can pass functions to other functions
3. Can return functions from functions

Question 5

Can you do this foo()()?

Answer 5

Yes it will call the inner function of foo()