CFP - Docs - defaultNullishValTo

defaultNullishValTo

(defaultVal: any) => (val: any) => any

Return a default value if a Nullish one is passed.

Try It

const defaultToNegativeOne = defaultNullishValTo(-1)

defaultToNegativeOne(1) // is 1
defaultToNegativeOne(0) // is 0
defaultToNegativeOne(undefined) // is -1
const defaultToNegativeOne = defaultNullishValTo(-1)

defaultToNegativeOne(1) // is 1
defaultToNegativeOne(0) // is 0
defaultToNegativeOne(undefined) // is -1

Try It

const defaultToNegativeOne =
  defaultNullishValTo(-1)

defaultToNegativeOne(1) // is 1
defaultToNegativeOne(0) // is 0
defaultToNegativeOne(undefined) // is -1
const defaultToNegativeOne =
  defaultNullishValTo(-1)

defaultToNegativeOne(1) // is 1
defaultToNegativeOne(0) // is 0
defaultToNegativeOne(undefined) // is -1

Sometimes we want a default value specifically when undefined or null are passed.

Below, we have the money per player in a game of Monopoly. Mike joined late, so he doesn't have a value yet. Let's start him off with 1500.

Try It

const players = {
  sam: 2000,
  jen: 0,
  mike: undefined,
}

const defaultTo1500 = defaultNullishValTo(1500)
const assignStartingMoney = mapValues(defaultTo1500)
const updatedPlayers = assignStartingMoney(players)

console.log(updatedPlayers)
// a new object {
//   sam: 2000,
//   jen: 0,
//   mike: 1500,
// }
type Players = Record<string, number | undefined>
const players: Players = {
  sam: 2000,
  jen: 0,
  mike: undefined,
}

const defaultTo1500 = defaultNullishValTo(1500)
const assignStartingMoney = mapValues(defaultTo1500<number>)<Players>
const updatedPlayers = assignStartingMoney(players)

console.log(updatedPlayers)
// a new object {
//   sam: 2000,
//   jen: 0,
//   mike: 1500,
// }

Try It

const players = {
  sam: 2000,
  jen: 0,
  mike: undefined,
}

const defaultTo1500 = defaultNullishValTo(1500)
const assignStartingMoney = mapValues(
  defaultTo1500
)
const updatedPlayers =
  assignStartingMoney(players)

console.log(updatedPlayers)
// a new object {
//   sam: 2000,
//   jen: 0,
//   mike: 1500,
// }
type Players = Record<string, number | undefined>
const players: Players = {
  sam: 2000,
  jen: 0,
  mike: undefined,
}

const defaultTo1500 = defaultNullishValTo(1500)
const assignStartingMoney = mapValues(
  defaultTo1500<number>
)<Players>
const updatedPlayers =
  assignStartingMoney(players)

console.log(updatedPlayers)
// a new object {
//   sam: 2000,
//   jen: 0,
//   mike: 1500,
// }