CODEWITHSUNDEEP
javascript
abhay
abhay

Reputation: 642

Place all empty values at last in array

I need to place all empty values at last in array. below code show what I try

1) This code sends all empty values at last in array but other values do not appear in a sorted manner.

var dateArray = [
  '','',
  new Date('2019-06-28',).toISOString().slice(0, 10).replace(/-/g, "."),
  '',
new Date('2019-06-01').toISOString().slice(0, 10).replace(/-/g, "."),
new Date('2019-06-02').toISOString().slice(0, 10).replace(/-/g, "."),
'',''
]
dateArray.sort(function(a, b) {
    return (a ==='') - (b ==='') || a - b;
});

console.log(dateArray)

2) When i remove this .toISOString().slice(0, 10).replace(/-/g, ".") it work as expected but showing complete date in output Fri Jun 28 2019 05:30:00 GMT+0530 (India Standard Time). I only need to show this format '2019.06.28'

var dateArray = [
  '','',
  new Date('2019-06-28',),
  '',
new Date('2019-06-01'),
new Date('2019-06-02'),
'',''
]
dateArray.sort(function(a, b) {
    return (a ==='') - (b ==='') || a - b;
});

console.log(dateArray)

Upvotes: 1

Views: 67

Answers (3)

Ghoul Ahmed
Ghoul Ahmed

Reputation: 4806

Try this:

const formatDate = (t)=>  t.getFullYear() +"."+ (t.getMonth() + 1) + "." + (""+t.getDate()).padStart(2,'0') 

var dateArray = [
  '','',
  formatDate(new Date('2019-06-28',)),
  '',
formatDate(new Date('2019-06-01')),
formatDate(new Date('2019-06-02')),
'',''
]


dateArray.sort(function(a, b) {
    return (a ==='') - (b ==='') ||  new Date(a) - new Date(b);
});

console.log(dateArray)

Upvotes: 1

Joppx
Joppx

Reputation: 82

How about this?

var dateArray = [
  '','',
  new Date('2019-06-28').toISOString().slice(0, 10).replace(/-/g, "."),
  '',
  new Date('2019-06-01').toISOString().slice(0, 10).replace(/-/g, "."),
  new Date('2019-06-02').toISOString().slice(0, 10).replace(/-/g, "."),
  '',''
]

dateArray.sort(function(a, b) {
    return (a ==='') - (b ==='') || new Date(a) - new Date(b);
});

Upvotes: 1

Jonas Wilms
Jonas Wilms

Reputation: 138267

Your last version works because

 new Date() - new Date()

will cast the dates to numbers (milliseconds since 1970) whereas:

  '2019-06-01' - '2019-06-01'

won't work as the strings can't be converted to numbers. Therefore a - b isn't tge right way to compare them. To compare strings, use a.localeCompare(b).

Upvotes: 3

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