Javascript

Question 1

Javascript

Variables

Answer 1

var dog;
let dog = 'string';
const dog;

Question 2

Javascript

How do you write the T/F boolean?

Answer 2

True
False

Question 3

Javascript

The Abscense of a value

Answer 3

Null

Question 4

Javascript

Undefined

Answer 4

A variable that does not yet have an assigned value

Question 5

Javascript

For giant math

Answer 5

BigInt

Question 6

Javascript

Symbol data type

Answer 6

const sym1 = Symbol();
const sym2 = Symbol("foo");
const sym3 = Symbol("foo");

sym2 != sym3 

Guaranteed unique

Question 7

Javascript

And

Answer 7

&&

Question 8

Javascipt

Or

Answer 8

||

Question 9

Javascript

Not

Answer 9

!

Question 10

Javascript

Difference between == & ===

Answer 10

3 === will check for strict equality. 
100 != "100"
2 equal objects will not be equal because they are different objects
!== will check for strict inequality

Question 11

Javascript

If Statements

Answer 11

if ('this' == false) {
   //do stuff
} else if ('this' == 'cake') {
  // other stuff
} else {
   //
}

Question 12

Javascript

Switch Statement

Answer 12

switch (place) {
    case 'first':
        // do stuff 
        break; 
    case 'second':
        // do stuff
        break;
    default: 
        break;
}

Question 13

Javascript

For Loop

Answer 13

for (var i = 5; i > 0; i--) {
    console.log(i);
};
console.log('Countdown finished!');

Question 14

Javascript

While Loop

Answer 14

var i = 5;
while (i > 0) {
    console.log(i);
    i = i - 1;
};
console.log('Counting completed!');

Question 15

Javascript

Functions

Answer 15

// A function that accepts two parameters
function letterFinder(word, match) {
    // do stuff 
}

Question 16

Javascript

Objects

Answer 16

var drone = {
    speed: 100,
    altitude: 200,
    color: "red"
}

var car = {};
car.color = "red";
car["color"] = "green";

Question 17

Javascript

Fat Arrow Functions

Answer 17

var addValues = (x, y) => {
  return x + y
}

asyncFunction()
  .then(() => asyncFunction1())
  .then(() => asyncFunction2())
  .then(() => finish);

Arrow functions shine best with anything that requires this to be bound to the context, and not the function itself.

Despite the fact that they are anonymous, I also like using them with methods such as map and reduce, because I think it makes my code more readable. To me, the pros outweigh the cons.