CFP - Docs - mPrependAll

mPrependAll

(prepended: array) => (base: array) => base

Prepend the contents of one array ahead of another

Consider prependAll instead.
This is for the uncommon case where mutating base is required.

Try It

const arr = ['c']
const prependAB = mPrependAll(['a', 'b'])
const mutatedArr = prependAB(arr)

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

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

Try It

const arr = ['c']
const prependAB = mPrependAll(['a', 'b'])
const mutatedArr = prependAB(arr)

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

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

Sometimes we want to mutate an array by prepending values ahead of it. Below, Sam is next in line for a roller coaster. Mike and Luke bought fast passes and want to join the line. Let's move them ahead of Sam.

Try It

const queue = ['sam', 'jen']

const cutInLine = mPrependAll(['mike', 'luke'])
cutInLine(queue)
console.log(queue)
// is ['mike', 'luke', 'sam', 'jen']
const queue = ['sam', 'jen']

const cutInLine = mPrependAll(['mike', 'luke'])
cutInLine(queue)
console.log(queue)
// is ['mike', 'luke', 'sam', 'jen']

Try It

const queue = ['sam', 'jen']

const cutInLine = mPrependAll(['mike', 'luke'])
cutInLine(queue)
console.log(queue)
// is ['mike', 'luke', 'sam', 'jen']
const queue = ['sam', 'jen']

const cutInLine = mPrependAll(['mike', 'luke'])
cutInLine(queue)
console.log(queue)
// is ['mike', 'luke', 'sam', 'jen']