How to check if values in an array of objects have a date format and how to reorder array by date if so?

Question

I have an array of data like so:

let arrayData =[
    {
        "category": "2019-07-24",
        "total": 1,
        "Col 1": 100
    },
    {
        "category": "2018-11-12",
        "total": 3,
        "Col 1": 101
    },
    {
        "category": "2019-07-11",
        "total": 1,
        "Col 1": 200
    },
    {
        "category": "2019-08-11",
        "total": 1,
        "Col 1": 153
    },
    {
        "category": "2019-09-25",
        "total": 1,
        "Col 1": 198
    }
]

How can I check if every 'category' value inside the array is in the format YYYY-MM-DD? And if so, re-order the objects inside the array by earliest date?

I know that I can use regex like so to check for individual dates:

checkIfDateIsInRightFormat() {
  // Is this the best way?
  const regex = /^\d{4}-\d{2}-\d{2}$/;

  if (dateStr.match(regex) === null) {
    return false;
  }

  const date = new Date(dateStr);

  const timestamp = date.getTime();

  if (typeof timestamp !== 'number' || Number.isNaN(timestamp)) {
    return false;
  }

  return date.toISOString().startsWith(dateStr);
}

and then I can do this:

let arrayOfItems = []

this.arrayData.foreach(item => {
     arrayOfItems.push(this.checkIfDateIsInRightFormat(item))
})

let result = arrayOfItems.every(element => {
    if (element === array[0] && element === true) {
      return true;
    }
});


if(result  === true) {
    // Here I'll order the objects in arrayData by earliest date in 'category'
    arrayData.sort(
      (objA, objB) => Number(objB.category) - Number(objA.category),
    );
}

However, it doesn't work as intended. How would I be able to achieve the right result?

Based on the arrayData above, the result should be:

let newArrayData =[
    {
        "category": "2018-11-12",
        "total": 3,
        "Col 1": 101
    },
    {
        "category": "2019-07-11",
        "total": 1,
        "Col 1": 200
    },
    {
        "category": "2019-07-24",
        "total": 1,
        "Col 1": 100
    },
    {
        "category": "2019-08-11",
        "total": 1,
        "Col 1": 153
    },
    {
        "category": "2019-09-25",
        "total": 1,
        "Col 1": 198
    }
]

Otherwise if I have something like this:

let exampleArrayData =[
    {
        "category": "2018-11-12",
        "total": 3,
        "Col 1": 101
    },
    {
        "category": "ABC",
        "total": 1,
        "Col 1": 200
    },
]

It would stop at finding out that they are not all dates. result = false.

Foxcode · Accepted Answer · 2022-12-08T11:38:37.647

Simplest way I think:

let newArrayData = false;
let arrayData =[
    {
        "category": "2019-07-24",
        "total": 1,
        "Col 1": 100
    },
    {
        "category": "2018-11-12",
        "total": 3,
        "Col 1": 101
    },
    {
        "category": "2019-07-24",
        "total": 1,
        "Col 1": 200
    },
    {
        "category": "2019-08-11",
        "total": 1,
        "Col 1": 153
    },
    {
        "category": "2019-09-25",
        "total": 1,
        "Col 1": 198
    }
];

if (arrayData.every(x => new Date(x.category) !== "Invalid Date"  && !isNaN(new Date(x.category)))){
    newArrayData = arrayData.slice().sort((a, b) => new Date(a.category) - new Date(b.category));
}

console.log(newArrayData);

.every() checks whether all items fulfill a condition.

By trying to convert the strings into a date, we can check whether they result in "Invalid Date" (which is returned by the new Date object in case of an invalid date) and if it is a number (ms since January 1, 1970). Now if you really want to make sure, that the strings are EXACTLY in YYYY-MM-DD format, then yes, you need regex, see: Regex date validation for yyyy-mm-dd

.slice() is only there to first make a copy of the array and can be omitted if you don't care about manipulating the original array, which .sort() otherwise does by default.

How to check if values in an array of objects have a date format and how to reorder array by date if so?

1 Answers1