JS Study Guide Cards

Question 1

t/f primitive datatypes are immutable

Answer 1

true

variables can be assigned to a new value but existing values cannot be changed

Question 2

const myDt = new Date();

Answer 2

today’s date and time

Question 3

dt.setDate(myDt + 10);

Answer 3

increment to 10 days from today

Question 4

dt = new Date(2008,12,30);

Answer 4

new date - 12/30/2008

Question 5

concat

“manu”.concat(“facture”);

Answer 5

// manufacture

Question 6

other string methods

Answer 6

includes
indexOf
charAt
match
replace

slice: The slice() method returns a shallow copy of a portion of an array into a new array object selected from start to end (end not included) where start and end represent the index of items in that array. The original array will not be modified.

substring vs. substr: The arguments of substring() represent the starting and ending indexes, while the arguments of substr() represent the starting index and the number of characters to include in the returned string.

Question 7

MAP

holds key/value pairs

Answer 7

map. set() - assigns value based on key
map. get() - get values based on key
map. has() = check existences