What Function Should I Use?

Ramda has nearly 200 functions so it can sometimes be difficult to know what to use and when. This is a non-exhaustive list of common actions you may wish to perform and the functions that are most likely to be suited to the task.

Type	Action	Function
List	change every value	map
	receive the index of each element along with the value when iterating over a list	addIndex
	pull a property off each value	pluck
	select values based on custom logic	filter
	select values from a specific index range	slice
	select values from the start	take
	select values from the start based on custom logic	takeWhile
	select values from the end	takeLast
	select values from the end based on custom logic	takeLastWhile
	remove the last value	init
	remove specific values	without
	remove values based on custom logic	reject
	remove all duplicates	uniq
	remove all duplicates based on custom logic	uniqWith
	remove values based on index	remove
	remove values from the start	drop
	remove values from the start based on custom logic	dropWhile
	remove values from the end	dropLast
	remove values from the end based on custom logic	dropLastWhile
	compute the sum	sum
	compute the product	product
	compute the average	mean
	compute the median	median
	compute based on custom logic and only output the final value	reduce / reduceRight
	compute based on custom logic and output the values as they are calculated	scan
	take the first value	head
	take the last value	last
	take a value from a specific index	nth
	take the first occurrence of a value based on custom logic	find
	take the last occurrence of a value based on custom logic	findLast
	know if a specific value is present	contains
	know where the first occurrence of a value is	indexOf
	know where the first occurrence of a value is based on custom logic	findIndex
	know where the last occurrence of a value is	lastIndexOf
	know where the last occurrence of a value is based on custom logic	findLastIndex
	know if a condition is satisfied by all of the values	all
	know if a condition is satisfied by any of the values	any
	know if a condition is satisfied by none of the values	none
	replace a value at a specific index	update
	replace a value at a specific index based on custom logic	adjust / lensPath
	add a value at the start	prepend
	add a value at the end	append
	add a value at a specific index	insert
	add multiple values at a specific index	insertAll
	group values based on custom logic	groupBy
	know how many values it contains	length
	get a specific range of integer values	range
	split at a specific index	splitAt
	split based on custom logic	splitWhen
	split into chunks of a specific length	splitEvery
	reverse	reverse
	sort	sort
	sort based on custom logic	sortBy
	concatenate two lists	concat
	find the common values in two lists	intersection
	find the common values in two lists based on custom logic	intersectionWith
	find the distinct values compared to another list	difference
	find the distinct values compared to another list based on custom logic	differenceWith
	combine two lists into a list of unique values	union
	combine two lists into a list of unique values based on custom logic	unionWith
	combine two lists into a list of pairs	zip
	combine two lists into a list of pairs based on custom logic	zipWith
	convert list of objects into one object	indexBy
Object	change every value	map / mapObjIndexed
	select a specific key's value	prop / path
	select a specific key's value or return a default if it is not found	propOr / pathOr
	select specific keys' values	props
	select specific keys	pick / pickAll
	select keys based on custom logic	filter / pickBy
	remove a specific key	dissoc / dissocPath
	remove specific keys	omit
	remove specific keys based on custom logic	reject
	add a specific key and value	assoc / assocPath
	replace a specific value based on custom logic	lens / lensProp / lensPath
	replace specific values based on custom logic	evolve
	know if a specific key is present	has / hasIn
	know if a specific key has a specific value	propEq / pathEq
	know if a specific key's value satisfies a custom predicate	propSatisfies / pathSatisfies
	know if specific keys have specific values	whereEq
	know if specific keys' values satisfy custom predicates	where
	list all the keys	keys / keysIn
	list all the values	values / valuesIn
	convert to a list of pairs	toPairs / toPairsIn
	know if two objects share the same key and value	eqProps
	create an object with a single key and value	objOf
	create an object with multiple keys and values	zipObj
	clone an object	clone
	merge two objects into one object	merge
	merge two objects into one object based on custom duplicate key logic	mergeWith
	merge more than two objects into one object	mergeAll
Functions	combine functions	compose / pipe
	combine promise returning functions	composeP / pipeP
	curry a function	curry
	partially apply a function	partial / partialRight
	uncurry a function	uncurry
	swap the argument order	flip
	apply a list of arguments	apply
	apply multiple functions to a single value and merge the results somehow	converge
	transform a function's arguments	useWith
	apply a list of functions to each argument and collect the results	juxt
	create a variadic function from one that takes an array	unapply
	restrict the number of accepted arguments to 1	unary
	restrict the number of accepted arguments to 2	binary
	restrict the number of accepted arguments to specific number	nAry
	return the supplied argument unchanged	identity
	turn a method into a function	invoker
	invoke a function only once	once
	inspect values without affecting them	tap
	bind to a specific context	bind
	lift a function	lift / liftN
	memoize	memoize
Logic	apply a function based on conditional logic	ifElse / cond / unless / when
	negate a value	not
	know if either of two values are truthy	or
	know if two values are truthy	and
	invert a predicate function	complement
	know if a value satisfies at least one of two predicates	either
	know if a value satisfies two predicates	both
	know if a value satisfies at least one of a list of predicates	anyPass
	know if a value satisfies at every one of a list of predicates	allPass
	produce an empty value	empty
	know if a value is empty	isEmpty
Relation	compare for value equality	equals
	compare for reference equality	identical
	know if a value is less than another	lt
	know if a value is less than or equal to another	lte
	know if a value is greater than another	gt
	know if a value is greater than or equal to another	gte
	find the smallest of two values	min
	find the smallest of two values based on custom logic	minBy
	find the largest of two values	max
	find the largest of two values based on custom logic	maxBy
Maths	increment a number by one	inc
	decrement a number by one	dec
	add two numbers	add
	subtract one number from another	subtract
	multiple two numbers	multiply
	divide one number by another	divide
	negate a number	negate
	divide one number by another and get the remainder	modulo / mathMod