CFP - Docs - discardFirst

discardFirst

(num: number) => (sequence: Sequence) => Sequence

Discard the first num values

Try It

const discardFirst2 = discardFirst(2)

discardFirst2(['a', 'b', 'c', 'd']) // is ['c', 'd']
discardFirst2('abcd') // is 'cd'
const discardFirst2 = discardFirst(2)

discardFirst2(['a', 'b', 'c', 'd']) // is ['c', 'd']
discardFirst2('abcd') // is 'cd'

Try It

const discardFirst2 = discardFirst(2)

discardFirst2(['a', 'b', 'c', 'd']) // is ['c', 'd']
discardFirst2('abcd') // is 'cd'
const discardFirst2 = discardFirst(2)

discardFirst2(['a', 'b', 'c', 'd']) // is ['c', 'd']
discardFirst2('abcd') // is 'cd'

Sometimes we get data in the form of arrays rather than objects. Below, we have chess results from a spreadsheet. Let's remove the first two columns of personal info.

Try It

const [_headers, ...chessResults] = [
  ['name', 'email', 'result', 'color'],
  ['luke', 'luke@example.com', 'win', 'white'],
  ['emma', 'emma@example.com', 'draw', 'black'],
]

const discardPersonalInfo = discardFirst(2)
const discardAllPersonalInfo = mapValues(discardPersonalInfo)

const updatedResults = discardAllPersonalInfo(chessResults)
console.log(updatedResults)
// is [
//   ['win', 'white'],
//   ['draw', 'black'],
// ]
const [_headers, ...chessResults] = [
  ['name', 'email', 'result', 'color'],
  ['luke', 'luke@example.com', 'win', 'white'],
  ['emma', 'emma@example.com', 'draw', 'black'],
]

const discardPersonalInfo = discardFirst(2)<string[]>
const discardAllPersonalInfo = mapValues(discardPersonalInfo)<string[][]>

const updatedResults = discardAllPersonalInfo(chessResults)
console.log(updatedResults)
// is [
//   ['win', 'white'],
//   ['draw', 'black'],
// ]

Try It

const [_headers, ...chessResults] = [
  ['name', 'email', 'result', 'color'],
  ['luke', 'luke@example.com', 'win', 'white'],
  ['emma', 'emma@example.com', 'draw', 'black'],
]

const discardPersonalInfo = discardFirst(2)
const discardAllPersonalInfo = mapValues(
  discardPersonalInfo
)

const updatedResults =
  discardAllPersonalInfo(chessResults)
console.log(updatedResults)
// is [
//   ['win', 'white'],
//   ['draw', 'black'],
// ]
const [_headers, ...chessResults] = [
  ['name', 'email', 'result', 'color'],
  ['luke', 'luke@example.com', 'win', 'white'],
  ['emma', 'emma@example.com', 'draw', 'black'],
]

const discardPersonalInfo = discardFirst(2)<
  string[]
>
const discardAllPersonalInfo = mapValues(
  discardPersonalInfo
)<string[][]>

const updatedResults =
  discardAllPersonalInfo(chessResults)
console.log(updatedResults)
// is [
//   ['win', 'white'],
//   ['draw', 'black'],
// ]