regex_capture_groups.js

const regex = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/u
const result = regex.exec('2018-07-05')

console.log(result[0]) // > '2018-07-05'
console.log(result[1]) // > '2018'
console.log(result[2]) // > '07'
console.log(result[3]) // > '05'

console.log(result.groups.year)  // > '2018'
console.log(result.groups.month) // > '07'
console.log(result.groups.day)   // > '05'