Author: John Au-Yeung

Sometimes, we want to get a date range using moment.js and JavaScript.

In this article, we’ll look at how to get a date range using moment.js and JavaScript.

How to get a date range using moment.js and JavaScript?

To get a date range using moment.js and JavaScript, we can use the moment add method.

For instance, we write:

const startDate = moment('2022-01-01')
const endDate = moment('2022-01-21')
let d = startDate
const range = []
while (+d.toDate() < +endDate.toDate()) {
  range.push(d.toDate())
  d = d.add(1, 'days')
}
console.log(range)

to set the start and end date of the range to startDate and endDate.

Then we set d to startDate.

Next, we use a while loop that runs until d is later than endDate.

In the loop, we call range.push with d.toDate() to push the moment object d converted to a date.

Then we call add with 1 and 'days' to add one day.

Therefore, range is has the dates from Jan 1, 2022 to Jan 20, 2022.

Conclusion

To get a date range using moment.js and JavaScript, we can use the moment add method.

Sometimes, we want to remove whitespaces with a regular expression and JavaScript.

In this article, we’ll look at how to remove whitespaces with a regular expression and JavaScript.

How to remove whitespaces with a regular expression and JavaScript?

To remove whitespaces with a regular expression and JavaScript, we can use the string replace method.

For instance, we write:

const str = "    bob is a good      boy     "
const s = str.replace(/^\s+|\s+$|\s+(?=\s)/g, "");
console.log(s)

to call str.replace with the /^\s+|\s+$|\s+(?=\s)/g regex.

The regex matches whitespaces at the start of a string with ^\s+.

It matches whitespaces at the end of a string with \s+$.

And it matches multiple whitespaces within the string with \s+(?=\s).

The g flag returns all matches in the string.

And then we replace them all with an empty string.

Therefore, s is 'bob is a good boy'.

Conclusion

To remove whitespaces with a regular expression and JavaScript, we can use the string replace method.

Sometimes, we want to convert strings to bigInt in JavaScript.

In this article, we’ll look at how to convert strings to bigInt in JavaScript.

How to convert strings to bigInt in JavaScript?

To convert strings to bigInt in JavaScript, we can use the BigInt function.

For instance, we write:

const string = '8795485488564835575723945398498489398434434';
const bigInt = BigInt(string);
console.log(bigInt)

to call BigInt with string to convert string to a bigint.

Therefore, bigInt is 8795485488564835575723945398498489398434434n .

Conclusion

To convert strings to bigInt in JavaScript, we can use the BigInt function.

Sometimes, we want to increment a numeric string by +1 with JavaScript.

In this article, we’ll look at how to increment a numeric string by +1 with JavaScript.

How to increment a numeric string by +1 with JavaScript?

To increment a numeric string by +1 with JavaScript, we can convert it to a number before incrementing it.

For instance, we write:

let pageID = '1'
pageID = parseInt(pageID) + 1;
console.log(pageID)

to call parseInt with pageID to convert the number string into a number.

Then we add 1 to it and assign the returned value back to pageID.

Therefore, pageID is 2 according to the console log.

Conclusion

To increment a numeric string by +1 with JavaScript, we can convert it to a number before incrementing it.

Sometimes, we want to compare 2 dates in format DD/MM/YYYY with JavaScript.

In this article, we’ll look at how to compare 2 dates in format DD/MM/YYYY with JavaScript.

How to compare 2 dates in format DD/MM/YYYY with JavaScript?

To compare 2 dates in format DD/MM/YYYY with JavaScript, we can convert each date string to a date.

For instance, we write:

const date1 = '25/02/1985';
const date2 = '26/02/1985';

const convertToDate = (d) => {
  const [day, month, year] = d.split("/");
  return new Date(year, month - 1, day);
}

console.log(convertToDate(date1) > convertToDate(date2))

to define the convertToDate function that takes the date string d.

In it, we call split with '/' to split the string by the slashes.

And then we destructure the date parts from the returned array and put them into the Date constructor.

We’ve to subtract month by 1 since JavaScript date’s months are zero-based.

Next, we call convertToDate with date1 and date2 and compare the 2 values.

Since date1 is earlier than date2, the console log should log false.

Conclusion

To compare 2 dates in format DD/MM/YYYY with JavaScript, we can convert each date string to a date.