How many numbers are extracted from a string of numbers?

node js, give a string composed of numbers, for example, "8910151821", how to get the number of numbers between 3 and 20 in this string, the result should be: 8, 9, 10, 10, 15, 18, a total of 5 numbers, 21 of which does not count, how can it be realized? Thank you

Javascript node.js
Sep.16,2021 
let compare = (d) => {
    return d > 3 && d < 20
}

'8910151821'.split('').map((d, i, arr) => {
    d = +d;
    if (i > 1) {
        let comD = arr[i - 1] * 10 + d;
        return compare(comD) ? comD : null
    } else if (compare(d)) {
        return d;
    }
}).filter(d => d);
const countNum = s => [...s].reduce((res, val) => {
  switch (true) {
    case !+val && res[2]:
      console.log('2' + val)
      res[0]PP
      res[2] = false
      break
    case +val > 2 && !res[1]:
      console.log(val)
      res[0]PP
      break
    case +val && +val < 3 && !res[1]:
      res[val] = true
      break
    case res[1]:
      console.log('1' + val)
      res[0]PP
      res[1] = false
      break
    default:
      [res[1], res[2]] = [false, false]
      break
  }
  return res
}, [0, false, false])[0]

countNum('8910151821')

is that what it means?

Previous: The problem of realizing JWT Refresh by integrating Shiro with SpringBoot

Next: The puppeteer crawl page appears 404, and the browser can open it normally.

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu