CFP - Docs - discardFirstWhile

discardFirstWhile

(predicate: Predicate) => (anArray: array) => array

Discard the first elements that pass a condition

Try It

const lt3 = n => n < 3
const discardFirstWhileLt3 = discardFirstWhile(lt3)

discardFirstWhileLt3([1, 2, 3, 4]) // is [3, 4]
discardFirstWhileLt3([3, 4, 1]) // is [3, 4, 1]
const lt3 = (n: number) => n < 3
const discardFirstWhileLt3 = discardFirstWhile(lt3)

discardFirstWhileLt3([1, 2, 3, 4]) // is [3, 4]
discardFirstWhileLt3([3, 4, 1]) // is [3, 4, 1]

Try It

const lt3 = n => n < 3
const discardFirstWhileLt3 =
  discardFirstWhile(lt3)

discardFirstWhileLt3([1, 2, 3, 4]) // is [3, 4]
discardFirstWhileLt3([3, 4, 1]) // is [3, 4, 1]
const lt3 = (n: number) => n < 3
const discardFirstWhileLt3 =
  discardFirstWhile(lt3)

discardFirstWhileLt3([1, 2, 3, 4]) // is [3, 4]
discardFirstWhileLt3([3, 4, 1]) // is [3, 4, 1]

This is useful when we have sorted data and don't need to filter over all of it. Below, we have a list of sorted test scores. We want to remove the zeroes since those students weren't in class.

Try It

const scores = [0, 0, 70, 88, 92]

const discardZeroes = discardFirstWhile(n => n === 0)
const updatedScores = discardZeroes(scores)
console.log(updatedScores)
// is [70, 88, 92]
const scores = [0, 0, 70, 88, 92]

const discardZeroes = discardFirstWhile((n: number) => n === 0)
const updatedScores = discardZeroes(scores)
console.log(updatedScores)
// is [70, 88, 92]

Try It

const scores = [0, 0, 70, 88, 92]

const discardZeroes = discardFirstWhile(
  n => n === 0
)
const updatedScores = discardZeroes(scores)
console.log(updatedScores)
// is [70, 88, 92]
const scores = [0, 0, 70, 88, 92]

const discardZeroes = discardFirstWhile(
  (n: number) => n === 0
)
const updatedScores = discardZeroes(scores)
console.log(updatedScores)
// is [70, 88, 92]