CFP - Docs - discardWhen

discardWhen

(predicate: Predicate) => (collection: Collection) => Collection

Discard entries that pass a condition

Try It

const gt2 = n => n > 2
const discardWhenGt2 = discardWhen(gt2)

const resultArr = discardWhenGt2([4, 1, 3, 2])
console.log(resultArr)
// is [1, 2]

const resultObj = discardWhenGt2({
  d: 4,
  a: 1,
  c: 3,
  b: 2,
})
console.log(resultObj)
// is { a: 1, b: 2 }
const gt2 = (n: number) => n > 2
const discardWhenGt2 = discardWhen(gt2)

const resultArr = discardWhenGt2([4, 1, 3, 2])
console.log(resultArr)
// is [1, 2]

const resultObj = discardWhenGt2({
  d: 4,
  a: 1,
  c: 3,
  b: 2,
})
console.log(resultObj)
// is { a: 1, b: 2 }

Try It

const gt2 = n => n > 2
const discardWhenGt2 = discardWhen(gt2)

const resultArr = discardWhenGt2([4, 1, 3, 2])
console.log(resultArr)
// is [1, 2]

const resultObj = discardWhenGt2({
  d: 4,
  a: 1,
  c: 3,
  b: 2,
})
console.log(resultObj)
// is { a: 1, b: 2 }
const gt2 = (n: number) => n > 2
const discardWhenGt2 = discardWhen(gt2)

const resultArr = discardWhenGt2([4, 1, 3, 2])
console.log(resultArr)
// is [1, 2]

const resultObj = discardWhenGt2({
  d: 4,
  a: 1,
  c: 3,
  b: 2,
})
console.log(resultObj)
// is { a: 1, b: 2 }

Sometimes we want to discard data. Below, we have an array of soda can weight measurements fresh off the assembly. We can't ship any outside our threshold of +/-0.02 fl oz from 12. Let's discard them.

Try It

const sodaWeights = [12, 11.99, 12.2, 11.88, 12.02]

const isOutsideThreshold = flOz => flOz > 12.02 || flOz < 11.98
const discardBadSodas = discardWhen(isOutsideThreshold)
const updatedSodas = discardBadSodas(sodaWeights)
console.log(updatedSodas)
// is [12, 11.99, 12.02]
const sodaWeights = [12, 11.99, 12.2, 11.88, 12.02]

const isOutsideThreshold = (flOz: number) => flOz > 12.02 || flOz < 11.98
const discardBadSodas = discardWhen(isOutsideThreshold)<number[]>
const updatedSodas = discardBadSodas(sodaWeights)
console.log(updatedSodas)
// is [12, 11.99, 12.02]

Try It

const sodaWeights = [
  12, 11.99, 12.2, 11.88, 12.02,
]

const isOutsideThreshold = flOz =>
  flOz > 12.02 || flOz < 11.98
const discardBadSodas = discardWhen(
  isOutsideThreshold
)
const updatedSodas = discardBadSodas(sodaWeights)
console.log(updatedSodas)
// is [12, 11.99, 12.02]
const sodaWeights = [
  12, 11.99, 12.2, 11.88, 12.02,
]

const isOutsideThreshold = (flOz: number) =>
  flOz > 12.02 || flOz < 11.98
const discardBadSodas = discardWhen(
  isOutsideThreshold
)<number[]>
const updatedSodas = discardBadSodas(sodaWeights)
console.log(updatedSodas)
// is [12, 11.99, 12.02]