CFP - Docs

set

(key: EntryKey, value: any) => (collection: EntryCollection) => EntryCollection

Set an entry key to a value

Try It

const obj = { a: 'b' }
const setAToC = set('a', 'c')
setAToC(obj) // is { a: 'c' }

const arr = ['a', '_', 'c']
const setIdx1ToB = set(1, 'b')
setIdx1ToB(arr) // is ['a', 'b', 'c']
const obj = { a: 'b' }
const setAToC = set('a', 'c')
setAToC(obj) // is { a: 'c' }

const arr = ['a', '_', 'c']
const setIdx1ToB = set(1, 'b')
setIdx1ToB(arr) // is ['a', 'b', 'c']

Try It

const obj = { a: 'b' }
const setAToC = set('a', 'c')
setAToC(obj) // is { a: 'c' }

const arr = ['a', '_', 'c']
const setIdx1ToB = set(1, 'b')
setIdx1ToB(arr) // is ['a', 'b', 'c']
const obj = { a: 'b' }
const setAToC = set('a', 'c')
setAToC(obj) // is { a: 'c' }

const arr = ['a', '_', 'c']
const setIdx1ToB = set(1, 'b')
setIdx1ToB(arr) // is ['a', 'b', 'c']

Sometimes we want to set a key to a value. Below, we are building an array of cast members for True Detective Season 1. Let's add a property 'isLead' using the set of lead members.

Try It

const topBilledCast = [
  { name: 'Matthew McConaughey' },
  { name: 'Woody Harrelson' },
  { name: 'Michelle Monaghan' },
  { name: 'Michael Potts' },
  { name: 'Tory Kittles' },
]

const leads = new Set(['Matthew McConaughey', 'Woody Harrelson'])
const flagLead = set('isLead', true)
const updateActor = actor => {
  return leads.has(actor.name) ? flagLead(actor) : actor
}
const flagAllLeads = mapValues(updateActor)
const updatedCast = flagAllLeads(topBilledCast)

console.log(updatedCast)
// is [
//   { name: Matthew McConaughey, isLead: true }
//   { name: Woody Harrelson, isLead: true }
//   { name: Michelle Monaghan }
//   { name: Michael Potts }
//   { name: Tory Kittles }
// ]
type Actor = {
  name: string
  isLead?: true
}
const topBilledCast: Actor[] = [
  { name: 'Matthew McConaughey' },
  { name: 'Woody Harrelson' },
  { name: 'Michelle Monaghan' },
  { name: 'Michael Potts' },
  { name: 'Tory Kittles' },
]

const leads = new Set(['Matthew McConaughey', 'Woody Harrelson'])
const flagLead = set('isLead', true)<Actor>
const updateActor = (actor: Actor) => {
  return leads.has(actor.name) ? flagLead(actor) : actor
}
const flagAllLeads = mapValues(updateActor)<Actor[]>
const updatedCast = flagAllLeads(topBilledCast)

console.log(updatedCast)
// is [
//   { name: Matthew McConaughey, isLead: true }
//   { name: Woody Harrelson, isLead: true }
//   { name: Michelle Monaghan }
//   { name: Michael Potts }
//   { name: Tory Kittles }
// ]

Try It

const topBilledCast = [
  { name: 'Matthew McConaughey' },
  { name: 'Woody Harrelson' },
  { name: 'Michelle Monaghan' },
  { name: 'Michael Potts' },
  { name: 'Tory Kittles' },
]

const leads = new Set([
  'Matthew McConaughey',
  'Woody Harrelson',
])
const flagLead = set('isLead', true)
const updateActor = actor => {
  return leads.has(actor.name) ?
      flagLead(actor)
    : actor
}
const flagAllLeads = mapValues(updateActor)
const updatedCast = flagAllLeads(topBilledCast)

console.log(updatedCast)
// is [
//   { name: Matthew McConaughey, isLead: true }
//   { name: Woody Harrelson, isLead: true }
//   { name: Michelle Monaghan }
//   { name: Michael Potts }
//   { name: Tory Kittles }
// ]
type Actor = {
  name: string
  isLead?: true
}
const topBilledCast: Actor[] = [
  { name: 'Matthew McConaughey' },
  { name: 'Woody Harrelson' },
  { name: 'Michelle Monaghan' },
  { name: 'Michael Potts' },
  { name: 'Tory Kittles' },
]

const leads = new Set([
  'Matthew McConaughey',
  'Woody Harrelson',
])
const flagLead = set('isLead', true)<Actor>
const updateActor = (actor: Actor) => {
  return leads.has(actor.name) ?
      flagLead(actor)
    : actor
}
const flagAllLeads = mapValues(updateActor)<
  Actor[]
>
const updatedCast = flagAllLeads(topBilledCast)

console.log(updatedCast)
// is [
//   { name: Matthew McConaughey, isLead: true }
//   { name: Woody Harrelson, isLead: true }
//   { name: Michelle Monaghan }
//   { name: Michael Potts }
//   { name: Tory Kittles }
// ]