CFP - Docs - mAppendOne

mAppendOne

(value: any) => (anArray: array) => anArray

Push a value onto an array

Consider appendOne instead.
This is for the uncommon case where mutating anArray is required.

Try It

const arr = ['a', 'b']
const pushC = mAppendOne('c')
const mutatedArr = pushC(arr)

console.log(mutatedArr === arr) // is true
console.log(arr) // is ['a', 'b', 'c']
const arr = ['a', 'b']
const pushC = mAppendOne('c')
const mutatedArr = pushC(arr)

console.log(mutatedArr === arr) // is true
console.log(arr) // is ['a', 'b', 'c']

Try It

const arr = ['a', 'b']
const pushC = mAppendOne('c')
const mutatedArr = pushC(arr)

console.log(mutatedArr === arr) // is true
console.log(arr) // is ['a', 'b', 'c']
const arr = ['a', 'b']
const pushC = mAppendOne('c')
const mutatedArr = pushC(arr)

console.log(mutatedArr === arr) // is true
console.log(arr) // is ['a', 'b', 'c']

Sometimes we want to mutate an array by pushing a value onto it. Below, our fast food joint has a super kitty promotion where every order gets a plushy. Let's add one to each order.

Try It

const orders = {
  mike: ['burger', 'fries'],
  luke: ['chicken sandwich', 'soda'],
}

const addSuperKitty = mAppendOne('super kitty')
const addSuperKitties = forEach(addSuperKitty)
addSuperKitties(orders)
console.log(orders)
// is {
//   mike: [burger, fries, super kitty]
//   luke: [chicken sandwich, soda, super kitty]
// }
type Orders = Record<string, string[]>
const orders: Orders = {
  mike: ['burger', 'fries'],
  luke: ['chicken sandwich', 'soda'],
}

const addSuperKitty = mAppendOne('super kitty')<string[]>
const addSuperKitties = forEach(addSuperKitty)<Orders>
addSuperKitties(orders)
console.log(orders)
// is {
//   mike: [burger, fries, super kitty]
//   luke: [chicken sandwich, soda, super kitty]
// }

Try It

const orders = {
  mike: ['burger', 'fries'],
  luke: ['chicken sandwich', 'soda'],
}

const addSuperKitty = mAppendOne('super kitty')
const addSuperKitties = forEach(addSuperKitty)
addSuperKitties(orders)
console.log(orders)
// is {
//   mike: [burger, fries, super kitty]
//   luke: [chicken sandwich, soda, super kitty]
// }
type Orders = Record<string, string[]>
const orders: Orders = {
  mike: ['burger', 'fries'],
  luke: ['chicken sandwich', 'soda'],
}

const addSuperKitty = mAppendOne('super kitty')<
  string[]
>
const addSuperKitties = forEach(
  addSuperKitty
)<Orders>
addSuperKitties(orders)
console.log(orders)
// is {
//   mike: [burger, fries, super kitty]
//   luke: [chicken sandwich, soda, super kitty]
// }