CFP - Docs - getKeys

getKeys

```
(collection: EntryCollection) => Keys
```

Return an array of the collection's keys

getKeys({ a: 1, b: 2 }) // is ['a', 'b']
getKeys({ a: 1, b: 2 }) // is ['a', 'b']

Try It

getKeys({ a: 1, b: 2 }) // is ['a', 'b']
getKeys({ a: 1, b: 2 }) // is ['a', 'b']

Sometimes we need the keys of a collection. Below, we have some 100-meter times. People who ran it in under 13 minutes qualify for the next round. Let's list the qualified runners.

Try It

const oneHundredMeterTimes = {
  mary: 12.8,
  sarah: 11.2,
  matt: 13.5,
}

const isSub13m = time => time < 13
const keepSub13Times = keepWhen(isSub13m)

const getQualifiedRunners = compose([keepSub13Times, Object.keys])

const qualified = getQualifiedRunners(oneHundredMeterTimes)
console.log(qualified)
// is [
//   mary
//   sarah
// ]
type Times = Record<string, number>
const oneHundredMeterTimes = {
  mary: 12.8,
  sarah: 11.2,
  matt: 13.5,
}

const isSub13m = (time: number) => time < 13
const keepSub13Times = keepWhen(isSub13m)<Times>

const getQualifiedRunners = compose([keepSub13Times, Object.keys])

const qualified = getQualifiedRunners(oneHundredMeterTimes)
console.log(qualified)
// is [
//   mary
//   sarah
// ]

Try It

const oneHundredMeterTimes = {
  mary: 12.8,
  sarah: 11.2,
  matt: 13.5,
}

const isSub13m = time => time < 13
const keepSub13Times = keepWhen(isSub13m)

const getQualifiedRunners = compose([
  keepSub13Times,
  Object.keys,
])

const qualified = getQualifiedRunners(
  oneHundredMeterTimes
)
console.log(qualified)
// is [
//   mary
//   sarah
// ]
type Times = Record<string, number>
const oneHundredMeterTimes = {
  mary: 12.8,
  sarah: 11.2,
  matt: 13.5,
}

const isSub13m = (time: number) => time < 13
const keepSub13Times = keepWhen(isSub13m)<Times>

const getQualifiedRunners = compose([
  keepSub13Times,
  Object.keys,
])

const qualified = getQualifiedRunners(
  oneHundredMeterTimes
)
console.log(qualified)
// is [
//   mary
//   sarah
// ]