My top JavaScript utilities, in just One Line of Code!

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What's your favorite one-liner in JavaScript?
Here are mine. And if you're a TypeScript fan, you'll be happy to know that most of these snippets work in TypeScript too.

Array

Intersperse element between elements
Generate an array of alphabet characters
Repeat an array
Find the index of the minimum item of an array
Find the index of the maximum item of an array
Get all arrays of consecutive elements
Cast a value as an array
Swap two array items
Remove duplicate values in an array
Get indices of a value in an array
Get all subsets of an array
Get all n-th items of an array
Sort an array of items by given key
Find the minimum item of an array by given key
Find the maximum item of an array by given key
Find the index of the last matching item of an array
Create cartesian product
Check if an array is empty
Count by the properties of an array of objects
Count the occurrences of array elements
Count the occurrences of a value in an array
Group an array of objects by a key
Swap the rows and columns of a matrix
Find the closest number from an array
Sort an array of numbers
Shuffle an array
Unzip an array of arrays
Zip multiple arrays
Split an array into chunks
Partition an array based on a condition
Compare two arrays regardless of order
Remove falsy values from array
Get union of arrays
Get the intersection of arrays
Clone an array
Compare two arrays
Convert an array of objects to a single object
Flatten an array
Find the length of the longest string in an array
Convert an array of strings to numbers
Merge two arrays
Get the unique values of an array
Get the sum of an array of numbers
Get the rank of an array of numbers
Get the average of an array
Find the minimum item of an array
Find the maximum item of an array
Empty an array
Create an array of numbers in the given range
Create an array of cumulative sum

DOM

Check if an element has overflow
Check if an element has CSS overflow
Check if two DOMRects intersect
Check if a given DOMRect is contained within another DOMRect
Compare two DOMRects for size and position match
Get the center point of a DOMRect
Calculate the distance to the bottom of a page
Get the position of an element relative to the document
Check if user scrolls to the bottom of the page
Serialize form data
Detect Internet Explorer browser
Check if the touch events are supported
Toggle an element
Strip HTML from a given text
Show an element
Scroll to top of the page
Replace an element
Reload the current page
Redirect to another page
Insert given HTML before an element
Insert given HTML after an element
Insert an element before other one
Insert an element after other one
Hide an element
Go back to the previous page
Get the selected text
Get all siblings of an element
Detect macOS browser
Check if an element is focused
Check if an element is a descendant of another

Date Time

Get the hours and minutes from the decimal time
Determine one year from now
Initialize the current date but set time to midnight
Get the total number of days in a year
Get the timezone string
Get the last date in the month of a date
Get the first date in the month of a date
Get the current quarter of a date
Add AM PM suffix to an hour
Calculate the number of months between two dates
Get the yesterday date
Get the tomorrow date
Get the day of the year from a date
Convert seconds to hh:mm:ss format
Format a date for the given locale
Get the weekday of a date
Get the month name of a date
Sort an array of dates
Get the number of days in given month
Get the current timestamp in seconds
Extract year, month, day, hour, minute, second and millisecond from a date
Convert a date to YYYY-MM-DD format
Compare two dates
Calculate the number of difference days between two dates

Function

Create a function that accepts a single argument
Box handler
Memoize a function
Uncurry a function
Curry a function
Check if a value is an async function
Check if a value is a generator function
Check if a value is a function
Partially apply a function
Logical xor operator
Execute a function once
Flip the arguments of a function
Delay the evaluation of a function
Compose functions from left to right
Identity function
Create an empty function
Compose functions

Math

Calculate the midpoint of a given range
Linear scale of a number between two ranges
Normalize the ratio of a number in a range
Calculate the linear interpolation between two numbers
Round a number to the nearest multiple of a given value
Calculate the midpoint between two points
Check if a rectangle overlaps other one
Check if a rectangle contains other one
Calculate the angle of a line defined by two points
Convert radians to degrees
Check if a point is inside a rectangle
Calculate the distance between two points
Convert degrees to radians

Misc

Wait for the next event loop
Convert an LCH color to a LAB color
Convert a LAB color to an LCH color
Check if the code is running in Jest
Clear all cookies
Convert Fahrenheit to Celsius
Generate an unique and increment id
Convert 3 digits color to 6 digits color
Convert URL parameters to object
Get type of a variable in string
Convert cookie to object
Get the first defined and non null argument
Redirect the page to HTTPS if it is in HTTP
Get the value of a cookie
Decode a JWT token
Convert Celsius to Fahrenheit
Wait for an amount of time
Encode a URL
Run Promises in sequence
Detect dark mode
Check if the code is running in the browser
Check if the code is running in NodeJS
Emulate a dice throw
Easing functions
Get the value of a param from a URL
Swap two variables
Convert rgb color to hex
Convert hex to rgb

Number

Get the intersection range between two ranges
Wrap a number between two values
Convert decimal to binary recursively
Truncate a number at decimal
Truncate a number to a given number of decimal places without rounding
Convert a number to equivalent characters
Calculate the factorial of a number
Round a number to a given number of digits
Get the arrays of digits from a number
Calculate Fibonacci numbers
Add an ordinal suffix to a number
Calculate the mod of collection index
Subtract arguments
Multiply arguments
Clamp a number between two values
Calculate the sum of arguments
Calculate the remainder of division of arguments
Calculate the division of arguments
Calculate the average of arguments
Prefix an integer with zeros
Compute the greatest common divisor between two numbers
Convert a string to number

Object

Returns an object with unique values by key
Sort an object by its properties
Remove all null and undefined properties from an object
Immutably rename object keys
Extract values of a property from an array of objects
Check if multiple objects are equal
Create an object from the pairs of key and value
Invert keys and values of an object
Shallow copy an object
Pick a subset of properties of an object
Omit a subset of properties from an object
Get the value at given path of an object
Create an empty map that does not have properties

Random

Generate a weighted random number in given range
Pick random lines from a text document
Pick a random property of an object
Generate a random sign
Get random items of an array
Get a random item and remove it from an array
Generate a random IP address
Generate a random string using Node crypto module
Generate an array of random integers in a given range
Generate a random UUID
Generate a random integer in given range
Generate a random floating point number in given range
Generate a random boolean
Generate a random string with given length
Generate a random string from given characters
Get a random item from an array
Generate a random hex color

String

Capitalize a string
Decode HTML entities
Convert an uint8 array to a base64 encoded string
Convert a base64 encoded string to an uint8 array
Format a string
Prepend a line number to each line of a text document
Remove duplicate lines of a text document
Reverse the order of lines of a text
Remove empty lines of a text document
Replace all tab characters with spaces
Sort lines of a text document in the alphabetical order
Count the number of words in a string
Check if a string consists of a repeated character sequence
Count the occurrences of a character in a string
Generate a hash of a string
Decapitalize a string
Swap case of characters in a string
Get the number of a character in a string
Convert a letter to associate emoji
Get the base URL without any parameters
Replace the first given number of characters of a string with another character
Strip ANSI codes from a string
Trim some character
Trim slashes at the beginning and the end of a string
Trim the file extension from a file name
Unescape HTML special characters
Truncate a string at full words
Escape HTML special characters
Convert the name of an Excel column to number
Check if a string is a palindrome
Sort the characters of a string in the alphabetical order
Get the length of a string in bytes
Convert a string to camelCase
Normalize file path slashes
Convert a Windows file path to Unix path
Convert a string to PascalCase
Check if a URL is absolute
Check if a path is relative
Convert snake_case to camelCase
Convert camelCase to kebab-case and vice versa
Replace multiple spaces with a single space
Check if two strings are anagram
Convert a string to URL slug
Uppercase the first character of each word in a string
Remove spaces from a string
Make the first character of a string lowercase
Reverse a string
Replace all line breaks with br elements
Repeat a string
Get the file name from a URL
Get the file extension from a file name

Validator

Check if a character is a digit
Check if a date occurs in the current year
Check if a value is base64 encoded
Check if a value is base58 encoded
Check if a value is base32 encoded
Check if a value is a business identifier code
Check if a string is an octal number
Check if a string is a MongoDB ObjectId
Check if a flat array has duplicate values
Check if a date is a weekend
Check if a date is a weekday
Check if a string is a hexadecimal number
Check if a string is a hexadecimal color
Check if a string contains only ASCII characters
Check if a string contains only letters and numbers
Check if a string contains only letters
Check if a value is a string
Check if a number is in a given range
Check if a string contains upper case characters
Check if a string contains lower case characters
Check if a value is a regular expression
Check if a value is an object
Check if a value is a plain object
Check if an array is subset of other array
Check if an array contains a value matching some criterias
Check if a string contains only digits
Check if all array elements are equal to a given value
Check if a number is positive
Check if a number is negative
Check if an object is a Promise
Check if an array is not empty
Check if a value is nil
Check if a number is odd
Check if a number is even
Check if a date is today
Validate a Gregorian date
Check if a value is a number
Check if an object is empty
Check if an object is an array
Check if all items in an array are equal
Check if a year is leap year
Check if a string is upper case
Check if a string is lower case
Check if a string contains whitespace
Check if a number is a power of 2
Check if a given integer is a prime number
Check if a date is between two dates

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