Enumerables

Question 1

returns true self == object, false otherwise

Answer 1

include?, member?

Question 2

returns true if all elements meet a specified criterion, false otherwise

Answer 2

all?

Question 3

returns true if any element meets a specified criterion, false otherwise

Answer 3

any?

Question 4

returns the count of elements, based on an argument or block criterion, if given

Answer 4

count

Question 5

returns a new hash containing the counts of each element

Answer 5

tally

Question 6

return a specified number of leading elements

Answer 6

take

Question 7

returns a specified number of trailing elements

Answer 7

drop

Question 8

returns the elements whose values are smallest among the element, as determined by <=> or a given block

Answer 8

min

Question 9

returns the elements whose values are largest among the elements, as determined by<=> or a given block

Answer 9

max

Question 10

Returns a 2-element Array containing the smallest and largest elements.

Answer 10

minmax

Question 11

Returns the smallest element, as determined by the given block.

Answer 11

min_by

Question 12

Returns the largest element, as determined by the given block.

Answer 12

max_by

Question 13

Returns an element selected by the block. find, detect

Answer 13

find, detect

Question 14

Returns elements selected by the block.

Answer 14

find_all, filter, select

Question 15

Returns the index of an element selected by a given object or block

Answer 15

find_index

Question 16

Returns elements that are not duplicates.

Answer 16

uniq

Question 17

Returns the elements, sorted by <=> or the given block.

Answer 17

sort

Question 18

Returns the elements, sorted by the given block.

Answer 18

sort_by

Question 19

Returns objects returned by the block.

Answer 19

map, collect

Question 20

Returns truthy objects returned by the block

Answer 20

filter_map

Question 21

Returns flattened objects returned by the block.

Answer 21

flat_map, collect_concat

Question 22

Returns the object formed by combining all elements.

Answer 22

reduce, inject

Question 23

Returns the sum of the elements, using method +++.

Answer 23

sum

Question 24

returns a boolean value if any of the object in the enumerable satisfies the given condition, else it returns false.

Answer 24

.any?

Question 25

returns a boolean value true if all the objects in the enumerable satisfies the given condition, else it returns false.

Answer 25

.all?

Question 26

returns a boolean value true if none of the objects in the enumerable satisfies the given condition, else it returns false.

Answer 26

.none?