Tuesday

Question 1

list the six falsy values.

also, describe how you’d use the Math object to remove a decimal from a number, round up a number, or round to the nearest integer.

Answer 1

false, 0, null, undefined, ‘’, NaN

Math.floor (num)
Math.ceil (num)
Math.round (num)

Question 2

use a method to determine if the letter r is present in str.
how would you change all of the ‘o’s to ‘a’s and the first instance of ‘t’ to ‘c’?

use a different method to determine if 14 is present in arr. what do you expect to return?

Answer 2

.includes ( )
.indexOf ( ), where -1 is returned if val not present

replace
replaceAll

Question 3

difference between the postfix and the prefix increment operator

Question 4

create a tally of these values using the reduce method :

const fruitBasket = [‘banana’, ‘cherry’, ‘orange’, ‘apple’, ‘cherry’, ‘orange’, ‘apple’, ‘banana’, ‘cherry’, ‘orange’, ‘fig’ ];

Answer 4

const count = fruitBasket.reduce( (tally, fruit) => {
tally[fruit] = (tally[fruit] || 0) + 1 ;
return tally;
} , {})