Intro to JS

Question 1

Truthy

Answer 1

values that are evaluated as true in a Boolean context

Question 2

Falsy

Answer 2

values that are evaluated as false in a Boolean context

Question 3

Automatic Semicolon Insertion (ASI)

Answer 3

TBD

Question 4

Type Coercion

Answer 4

TBD

Question 5

Expression

Answer 5

code that returns a value

4 + 5; myVariable; Math.random();

Question 6

Statement

Answer 6

code that performs an action

if..else; try…catch; switch;

Question 7

hoisting: functions

Answer 7

yes

Question 8

hoisting: variables

Answer 8

also yes, but in lines before attribution will evaluate to undefined

Question 9

undefined

Answer 9

placeholder for a (assumed) future value;
the air inside a container before the container is used

Question 10

Number.isNaN or isNan

Answer 10

Number.isNaN
isNan(“string”) === true

Question 11

globalThis

Answer 11

reference to the global this (window)

Question 12

try..catch block has ? many components

Answer 12

try {…} catch(err) {…} finally {…}

Question 13

if there are 2 try..catch..finally, one nested, what happens if the inner catch throws an error and inner finally returns a value

Answer 13

outer catch will not ‘catch’ error thrown by inner catch

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try…catch#returning_from_a_finally-block