How to sort moment-timezone list?

Question

I want to show the moment-timezone list in ascending order in a drop-down menu. By default, those are sorted in alphabetical order. But, my requirement is to sort them by GMT in ascending order.

before soring:

[
  '(GMT+00:00) Africa/Abidjan',
  '(GMT+00:00) Africa/Accra',
  '(GMT+03:00) Africa/Addis_Ababa',
  '(GMT+01:00) Africa/Algiers',
  '(GMT+03:00) Africa/Asmara',
  '(GMT+03:00) Africa/Asmera',
  '(GMT+00:00) Africa/Bamako',
  '(GMT+01:00) Africa/Bangui',
]

after sorting:

[
  '(GMT+00:00) Africa/Abidjan',
  '(GMT+00:00) Africa/Accra',
  '(GMT+00:00) Africa/Bamako',
  '(GMT+01:00) Africa/Algiers',
  '(GMT+01:00) Africa/Bangui',
  '(GMT+03:00) Africa/Addis_Ababa',
  '(GMT+03:00) Africa/Asmera',
  '(GMT+03:00) Africa/Asmara',
]

Answer 1

Shorter than yours, Ashik. No need to access the timezone from the array twice

const getTimeZoneList = moment.tz.names()
  .map(t => `(GMT${moment.tz(t).format("Z")}) ${t}`);
const sortByZone = (a,b) => { 
  let [ahh,amm] = a.split("GMT")[1].split(")")[0].split(":"); 
  let [bhh,bmm] = b.split("GMT")[1].split(")")[0].split(":");
  return (+ahh*60+amm) - (+bhh*60+bmm)
};
console.log(getTimeZoneList.sort(sortByZone))

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