Now we’re getting to It

Question 1

JS: (expression) === VAR ? true: false;

Answer 1

Ternary operator evaluating for a Boolean response

Question 2

JS: (expression) === VAR ? true :
(expression) ? true : false;

Answer 2

Nested ternary: basically if, else if, else
If the first returns false it moves into second line

Question 3

JS: for (const VAR of ARRAY/STR) {
do something;
}

Answer 3

Basic for … of loop. Ideal to iterate thru arrays and strings

Question 4

JS: const { key } = object;
console.log(key);
// prints ‘value’

Answer 4

A destructured assignment
Instead of
const key = object.key;

Question 5

JS: const {key} = object;

key.nestedProperty;
or
key.nestedMethod();

Answer 5

More destructured assignment to access a nested property

Question 6

JS: array.forEach(item => do something));

Answer 6

Array iterator .
NB .forEach well return undefined so you need to do something with it

Question 7

JS; const newArray = array.map(item => {
doSomethingWith item;
});

Answer 7

The .map method.
Very similar to .forEach but returns an array

Question 8

JS: .findIndex()

Answer 8

Use much like .map and .foreach

Question 9

JS: array.some()

Answer 9

Interator method that will check if there are ‘some’ given is criteria and return Boolean

Question 10

JS: array.filter()

Answer 10

Iterator checking criteria and returns a new array

Question 11

JS: array.reduce((accumulator, current) => {
return accumulator + current;
})

Question 12

JS: let variable = thisVar || ‘that string’;
Do something;

Answer 12

Short circuit evaluation (of an single if/else)
Eg.
if ‘thisVar’ exists use it,
else default to ‘that string’