CFP - Docs - expandStart

expandStart

(length: number, char: Character) => (aString: string) => string

Expand a string to length by prepending char

Try It

const expandTo3 = expandStart(3, '-')

expandTo3('a') // is '--a'
expandTo3('ab') // is '-ab'
expandTo3('abc') // is 'abc'
const expandTo3 = expandStart(3, '-')

expandTo3('a') // is '--a'
expandTo3('ab') // is '-ab'
expandTo3('abc') // is 'abc'

Try It

const expandTo3 = expandStart(3, '-')

expandTo3('a') // is '--a'
expandTo3('ab') // is '-ab'
expandTo3('abc') // is 'abc'
const expandTo3 = expandStart(3, '-')

expandTo3('a') // is '--a'
expandTo3('ab') // is '-ab'
expandTo3('abc') // is 'abc'

Sometimes we want a string to have a certain length. Below, we normalize file IDs so they sort as expected.

Try It

const profilePictureIds = [196, 22081, 352, 78]
const addLeadingZeroes = expandStart(5, '0')
const sortedFileNames = profilePictureIds
  .map(id => {
    const normalizedId = addLeadingZeroes(`${id}`)
    return `profile-picture-${normalizedId}.jpg`
  })
  .toSorted()
  .join('\n')

console.log(sortedFileNames)
// is
// profile-picture-00078.jpg
// profile-picture-00196.jpg
// profile-picture-00352.jpg
// profile-picture-22081.jpg
const profilePictureIds = [196, 22081, 352, 78]
const addLeadingZeroes = expandStart(5, '0')
const sortedFileNames = profilePictureIds
  .map((id: number) => {
    const normalizedId = addLeadingZeroes(`${id}`)
    return `profile-picture-${normalizedId}.jpg`
  })
  .toSorted()
  .join('\n')

console.log(sortedFileNames)
// is
// profile-picture-00078.jpg
// profile-picture-00196.jpg
// profile-picture-00352.jpg
// profile-picture-22081.jpg

Try It

const profilePictureIds = [196, 22081, 352, 78]
const addLeadingZeroes = expandStart(5, '0')
const sortedFileNames = profilePictureIds
  .map(id => {
    const normalizedId = addLeadingZeroes(`${id}`)
    return `profile-picture-${normalizedId}.jpg`
  })
  .toSorted()
  .join('\n')

console.log(sortedFileNames)
// is
// profile-picture-00078.jpg
// profile-picture-00196.jpg
// profile-picture-00352.jpg
// profile-picture-22081.jpg
const profilePictureIds = [196, 22081, 352, 78]
const addLeadingZeroes = expandStart(5, '0')
const sortedFileNames = profilePictureIds
  .map((id: number) => {
    const normalizedId = addLeadingZeroes(`${id}`)
    return `profile-picture-${normalizedId}.jpg`
  })
  .toSorted()
  .join('\n')

console.log(sortedFileNames)
// is
// profile-picture-00078.jpg
// profile-picture-00196.jpg
// profile-picture-00352.jpg
// profile-picture-22081.jpg