Create a single array from returned strings

Question

I have a for loop that goes through all elements of a certain class and returns the value (which in my case it's a date — e.g. 2020-05-15) and splits it. So I get multiple arrays from which I want to create one joined array of all years without duplicates.

My code is basic right now, but I'm constantly running into troubles.

function getDate () {
        for (var i = 0; i < total; i++) {
            var dateSplit = elements.date[i].innerText.split('-'); 
            // this returns multiple arrays of {'year', 'month', 'day'}
            var dateOnly = dateSplit[0] // returns multiple strings of years
        }
}

How do i join dateOnly into one array?

Do you get multiple arrays or multiple array items ? There's a difference between the two — Kunal Mukherjee
– Kunal Mukherjee, Commented Feb 22, 2021 at 9:46

Nina Scholz · Accepted Answer · 2021-02-22 09:46:39Z

3

You could collect the years in a Set and return an array of unique values.

function getDate() {
    const years = new Set;
    for (var i = 0; i < total; i++) {
        years.add(+elements.date[i].innerText.split('-', 1)[0]);
    }
    return [...years];
}

answered Feb 22, 2021 at 9:46

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

DBS Over a year ago

What does the + in +elements.date[i] do? Is that just string to number conversion?

Kunal Mukherjee Over a year ago

@DBS it converts the string to Number

Nina Scholz Over a year ago

right it is an unary plus + fo conversion to number.

Randall Over a year ago

@NinaScholz why you invoke Set without parenthesis?

Nina Scholz Over a year ago

@Randall, new operator calls the constructor/function and returns an instance. i need no parameter for an empty set. if you like to chain the instance, you need some braces.

Jobelle · Accepted Answer · 2021-02-22 11:56:48Z

0

Try the below

function getYearAsArray(p1, p2) {
  var temp = ['2025-05-15', '2092-05-15', '2021-05-15', '2021-05-15'];
  
 var result =  temp.map(i=> {
  return i.replace(/^(\d{4})(-\d{2}-\d{2})$/, '$1');
  });
 
  return [...new Set(result)];;
}

Check this

answered Feb 22, 2021 at 11:56

Jobelle

2,8441 gold badge17 silver badges27 bronze badges

Collectives™ on Stack Overflow

Create a single array from returned strings

2 Answers 2

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related