Check if date is a valid one

Question

Following is the scenario:

I have a String date and a date format which is different. Ex.:
date: 2016-10-19
dateFormat: \"DD-MM-YYYY\".

Answer 1

console.log(` moment('2019-09-01', 'YYYY-MM-DD').isValid()?  ` +moment('2019-09-01', 'YYYY-MM-DD').isValid())
console.log(` moment('2019-22-01', 'YYYY-DD-MM').isValid()?  ` +moment('2019-22-01', 'YYYY-DD-MM').isValid())
console.log(` moment('2019-22-22', 'YYYY-DD-MM').isValid()?  ` +moment('2019-22-22', 'YYYY-DD-MM').isValid())
console.log(` moment('undefined', 'YYYY-DD-MM').isValid()?  ` +moment('undefined', 'YYYY-DD-MM').isValid())

 moment('2019-09-01', 'YYYY-MM-DD').isValid()?  true
 moment('2019-22-01', 'YYYY-DD-MM').isValid()?  true
 moment('2019-22-22', 'YYYY-DD-MM').isValid()?  false
 moment('undefined', 'YYYY-DD-MM').isValid()?  false