30 Super Useful JavaScript One-Liners
Save time in your day-to-day work and have fun with them
In this post, I list a series of 30 one-liners in JavaScript that are very useful when developing using vanilla js ( ≥ ES6). They are also an elegant way to solve problems using all the power the language offers us in the latest versions.
I have grouped them into the following categories:
- Date
- Strings
- Numbers
- Arrays
- Utils
Without further ado, I’ll get to it. I hope you find them helpful!
Dates
1. Knowing if a date corresponds to the current date
As simple as converting the two dates to the same format and comparing them.
2. How to know if a date is between two dates
We check if the past date is within the min-max range.
3. How to know if a date falls on a weekend
The getDay method returns a number between 0 and 6, representing the day of the week for the given date.
4. Check if a date is in a year
Similar to when we used to check if a date corresponded to the current day. In this case, we get the year and compare it.
5. Convert an hour to AM-PM format
We can use mathematical expressions to determine whether the elapsed time is less than 13 hours or more and thus determine whether it is “AM” or “PM.”
Strings
6. Capitalize the first letter of a sentence
We convert the first letter to capital letters and then append the rest of the letters of the sentence using
7. Convert a letter to his associate emoji
8. How to know if a string is a palindrome
Numbers
9. How to calculate the factorial of a number
10. How to obtain the Fibonacci of a number
11. How to obtain the factorial of a number
Arrays
12. Copy an array to another array
13. Get the unique elements from an Array
14. Shuffle Array
The following snippet shuffles an array in a very efficient way.
15. Group an Array by a property
16. Reverse a String
We can utilize the built-in Array methods like reverse() and join() to create a one-liner that does the same thing.
17. Check if two arrays contain the same values
We can use Array.sort() and Array.join() methods to check if two arrays contain the same values.
Utils
18. Convert to Fahrenheit
19 . Convert to Celsius
20. How to clear all cookies from the browser
21. How to convert from HEX to RGB
22. How to convert from RGB to HEX
23. Check if a function is an Async function
24. How to know if a code is running in the browser
25. How to know if a code is running in node
26. Detect Dark Mode
This a very handy way to check if the user has dark mode enabled on their browser.
27. Scroll to the Top
A one-line way to scroll elements is to use the
28. Scroll to Bottom
29. Convert a JSON to a Map
This function lets us convert a Map object to a JSON string in a simple way.
30. Generate a 128-bit UUID
This function allows us to generate a UUID with a 128-bit value for uniquely identifying an object or entity.
Final Throughs
If you have reached this point, you probably already have your own opinion about one-liners. For me, one-liners (JavaScript, Linux,…) are a compact and elegant way to solve problems, but you also have to be careful that the solution is not too difficult to read.
Other useful one-liners
https://betterprogramming.pub/25-awesome-linux-command-one-liners-9495f26f07fb
