7 killer JavaScript One-Liners You Must Know 😎😎

top 7 best killer javascript one liners that you must know in your code journey

Generate random string

if you will ever need a temporary uniques id for something, this is one liner will generate a random string for you

const randomString = Math.random().toString(36).slice(2);
console.log(randomString)

extract domain name from an email

you can use the substring() method to extract the domain name of the email

let email = 'admin@ashishdonga.me';
let getDomain = email.substring(email.indexOf('@') + 1);

console.log(getDomain)

detect dark mode

with this one linera you can check if the user is using dark mode and then you can update some functionality according to dark mode

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

*check if an element is focused *

to detect if the element has the focus in javascript, you can use the read only javascript property activeElement of the document object

const elem = document.querySelector('.text-input')
const isFocus = elem = document.activeElement;

Redirecting User

you can redirect the user to any specific URL using Javascript

const redirect = url => location.href = url

check if a variable is an array

you can check if any variable is an array or not using the Array.isArray() method

let fruit = 'apple';
let fruits = ['apple','banana','mango','orange','grapes']

const isArray = (arr) => Array.isArray(arr)

console.log(isArray.fruit); // false
console.log(isArray.fruits); //true

check if an array is empty

this is one liner will let you know if an array is empty or not

let arr1 = []
let arr2 = [2,4,6,8,10]

const arr1IsEmpty = !(Array.isArray(arr1) && arr1.length >0);
const arr2IsEmpty = !(Array.isArray(arr2) && arr2.length >0);

console.log(arra1);
console.log(arr2)

read more

12 javascript pro snippet codes for everyday problems

What is difference between undefined & null in javascript ?

share this JavaScript One-Liners article with your friends