12 Javascript One liners That’ll make your life easier

Today we discuss one liners to improve productivity and skills, which we can use in our daily development life.

1. Uppercase the first character of each word in a string

This method is used to To achieve the capitalization of the first letter of each word in a string in JavaScript.

const uppercaseWords = (str) => str.replace(/^(.)|\s+(.)/g, (c) => c.toUpperCase())

uppercaseWords('hello world'); // 'Hello World'

2. Convert a string to Camelcase

const toCamelCase = (str) => str.trim().replace(/[-_\s]+(.)?/g, (_, c) => (c ? c.toUpperCase() : ''));

toCamelCase('camel-case'); // camelCase
toCamelCase('-webkit-scrollbar-thumb'); // WebkitScrollbarThumb
toCamelCase('_hello_world'); // HelloWorld
toCamelCase('hello_world'); // helloWorld

3. Remove Duplicate from Array

By Using Set we can easily remove duplicates in JavaScript. Its a life saver.

const removeDuplicates = (arr) => [...new Set(arr)];

console.log(removeDuplicates([1, 2, 3, 3, 4, 4, 5, 5, 6]));
// Result: [ 1, 2, 3, 4, 5, 6 ]

4. Check if number is even or odd

It’s very easy to find out given number is even or odd

const isEven = num => num % 2 === 0

isEven(2) // true
isEven(1) // false

5. Find Average of Numbers

You can find the average between multiple numbers using reduce method.

const average = (...args) => args.reduce((a, b) => a + b) / args.length;

average(1, 2, 3, 4);
// Result: 2.5

6. Scroll to Top

You can use window.scrollTo(0, 0) method to automatic scroll to top. Set both x and y as 0.

const goToTop = () => window.scrollTo(0, 0);

goToTop();

7. Reverse a String

You can easily reverse a string using split, reverse and join methods.

const reverse = str => str.split('').reverse().join('');

reverse('hello world');     
// Result: 'dlrow olleh'

8. Check if array is empty

Simple one liner to check if an array is empty, will return true or false.

const isNotEmpty = arr => Array.isArray(arr) && arr.length > 0;

isNotEmpty([1, 2, 3]);
// Result: true

9. Get Selected Text

Get the text the user has select using inbuilt getSelection property.

const getSelectedText = () => window.getSelection().toString();

getSelectedText();

10. Detect Dark Mode

Check if a user’s device is in dark mode with the following code.

const isDarkMode = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches

console.log(isDarkMode) // Result: True or False

11. Remove falsy values from array

Using this method, you will be able to filter out all falsy values in the array.

const removeFalsy = (arr) => arr.filter(Boolean)

removeFalsy([0, 'a string', '', NaN, true, 5, undefined, 'another string', false])
// ['a string', true, 5, 'another string']

12. Calculate the number of different days between two dates

we can calculate the number of days between two dates with the following code.

const diffDays = (date, otherDate) => Math.ceil(Math.abs(date - otherDate) / (1000 * 60 * 60 * 24));

diffDays(new Date("2021-11-3"), new Date("2022-2-1"))  // 90

Wrapping Up

Hope you enjoyed the article 🙌