CFP - Docs - pruneStart

pruneStart

(pruneArg: Character | Character[]) => (aString: string) => string

Prune characters off the start of a string

Try It

const pruneInitialDashes = pruneStart('-')

pruneInitialDashes('--abc--') // is 'abc--'
const pruneInitialDashes = pruneStart('-')

pruneInitialDashes('--abc--') // is 'abc--'

Try It

const pruneInitialDashes = pruneStart('-')

pruneInitialDashes('--abc--') // is 'abc--'
const pruneInitialDashes = pruneStart('-')

pruneInitialDashes('--abc--') // is 'abc--'

Sometimes we want to remove characters from the start of strings. Below, we have a price-searching tool that unfortunately gives us raw strings. Let's prune the known characters and turn the prices into numbers. Then we can get the best price.

Try It

const rawPricesFound = ['$24.50', '22.99', '• $28.00']

const getPrice = compose([pruneStart([' ', '•', '$']), Number])
const getBestPrice = compose([mapValues(getPrice), getMinValue])

const bestPrice = getBestPrice(rawPricesFound)
console.log(bestPrice)
// is 22.99
const rawPricesFound = ['$24.50', '22.99', '• $28.00']

const getPrice = compose([pruneStart([' ', '•', '$']), Number])
const getBestPrice = compose([mapValues(getPrice)<string[]>, getMinValue])

const bestPrice = getBestPrice(rawPricesFound)
console.log(bestPrice)
// is 22.99

Try It

const rawPricesFound = [
  '$24.50',
  '22.99',
  '• $28.00',
]

const getPrice = compose([
  pruneStart([' ', '•', '$']),
  Number,
])
const getBestPrice = compose([
  mapValues(getPrice),
  getMinValue,
])

const bestPrice = getBestPrice(rawPricesFound)
console.log(bestPrice)
// is 22.99
const rawPricesFound = [
  '$24.50',
  '22.99',
  '• $28.00',
]

const getPrice = compose([
  pruneStart([' ', '•', '$']),
  Number,
])
const getBestPrice = compose([
  mapValues(getPrice)<string[]>,
  getMinValue,
])

const bestPrice = getBestPrice(rawPricesFound)
console.log(bestPrice)
// is 22.99