Library

Implement equations using the Array.of() method to create arrays.

Write a function that checks if a given variable is an array. If it is an array, return true, otherwise return false.

Given an array of numbers, use reduce method to obtain a single value that represents the sum of all numbers in the array.

Write a function that returns an array of char codes from a string

Given a string, return a new string that is a substring of the original string. The substring should start at a specified index and continue until the end of the original string.

Implement an algorithm that manages the overbooking of an airline flight.

Write a function that uses the Date.prototype.getDay() method to determine the day of the week for a given date object.

Write a function that takes a Set object as a parameter and returns an array of keys using Set.prototype.keys().

Complete the functions provided to properly utilize the Date.now() method.

Given a date, return the UTC date.

Write a function that returns a substring of a given string, based on the start and end index provided

Write a function that checks if an element is present in an array using Array.prototype.includes() method.

Convert an array to a string with comma-separated values. The input array can contain numbers, strings, objects, or arrays.

Implement a function that groups the elements of an array based on a given predicate function.

Create a function to search for a substring in a given string using String.prototype.search() method.

Create a function that takes an array and removes a portion of the array, as specified by the arguments, and returns the removed portion.

Create a function that receives a Date object and returns the milliseconds that have elapsed since the start of the day.

Create a function that uses the String.prototype.lastIndexOf() method to find the index of the last occurrence of a specified substring in a given string.

Create a function that takes a string as input and returns the string in all lowercase letters.

Create a function that takes a string and a number and pads that string with a specified character until it reaches the given length.

Write a function that takes a string and returns an array of code points for each character in the string using String.prototype.codePointAt() method.

Write a function that takes a string and returns an array of matched patterns using String.prototype.matchAll().

Write a function that takes an array of numbers and returns their sum, using Array.prototype.reduceRight().

Create a function that takes in a string with extra white space at the beginning and end of the string, and returns a new string with that white space removed. Use String.prototype.trim().

Create a function that takes in a string and a length and returns a new string with the original string padded with leading spaces if it is shorter than the provided length.

Use Array.prototype.slice() to solve the following tasks.

Write a function that loops through a Set using Set.prototype.forEach() method and returns an array containing the results of applying the provided function to each element.

Implement a function that takes an array of strings and a search string, and returns a new array containing only the strings that includes the search string using String.prototype.includes() method.

Implement a function that removes all unused items in a Set collection

Create a function that determines if two strings are anagrams of each other.

Create a function that takes a year (YYYY) and returns the date object with its year set to the provided year.

Implement a function that concatenates a given string 'n' times using the String.prototype.repeat() method.

Create a function that takes in two parameters, a string and a substring, and checks if the string includes the substring. Return a boolean value.

Write a function that takes a string and a regular expression and returns an array of all the substrings in the string that match the regular expression.

Write a function that takes an array and a value as arguments and returns the index of the last occurrence of that value in the array using Array.prototype.lastIndexOf(). If the value is not found, return -1.

Write a function that joins two arrays into a single string using Array.prototype.join() method.

Write a function that returns the index of the first occurrence of a given element in an array using Array.prototype.indexOf(). If the element is not found in the array, return -1.

Create a function that uses Array.prototype.findLast() to find the last element in an array that matches a given condition. Return the element if it exists or null if it does not.

Write a function that flattens nested arrays using Array.prototype.flat() method.

Implement a function that adds a value to a set using Set.prototype.add().

Fill arrays with specific values using Array.prototype.fill()

Write a function that checks if every element in an array satisfies a given condition.

Implement a function that takes a string as input and returns it in lower case.

Create a function that accepts a Set and a value to remove, and returns the updated Set after deleting the value.

Create a function that takes an array and a value as arguments and adds the value to the beginning of the array using the unshift() method.

Create a function that uses Array.prototype.entries() to iterate over an array and perform some operations.

Create a function that uses the String.prototype.replaceAll() method to replace all occurrences of a given substring within a string.

Write a function that takes a string and removes any trailing whitespace at the end of it using String.prototype.trimEnd().

Create a function that returns an array of values of an array using the Array.prototype.values() method.

Create a function that slices a string based on a given start and end indexes

Implement a function that takes in a Set and returns an array of entries

Create a function that returns the current year using Date's built-in getFullYear method

This kata focuses on using String.prototype.indexOf() method.

Write a function that checks if a given string has a unicode character code point greater than or equal to 128. Use the String.prototype.codePointAt() method.

Create a function that removes white space at the end of a given string using String.prototype.trimEnd().

Create a function that takes an array and reverse its order in place.

Implement a function that returns the character at the specified index of a given string.

Write a function that takes an integer n and returns the nth Fibonacci number using recursion.

Create a function that returns the current date as a number (1-31).

Sort an array of words based on their alphabetical order using String.prototype.localeCompare() method.

Create a function that sets the UTC month of a given date object.

Implement the Array.prototype.with() method that returns a new array with the elements from the original array and the added elements.

Create a function that receives a string and a number n, the function should return the string repeated n times.

Implement a function that groups an array of objects by a given key and returns a new array of objects, where each object has a key and an array of objects that have that key.

Write a function that returns the result of a string match with a given pattern.

Write a function that returns whether a given string ends with the provided suffix or not

Implement normalize method to format a string removing all the accents

Given an array of person objects, sort them alphabetically by their last name using String.prototype.localeCompare().

Write a function that accepts a date object and a number of seconds (0 - 59) and returns a new date object with the seconds set to the provided value. The operation should be done using the setUTCSeconds() method.

Create a function that counts the number of seconds in a given timestamp

Create a function that checks if a given string ends with a specified suffix.

Write a function that checks if a given string includes a specific substring. Use String.prototype.includes() method.

Create a function that takes an array of numbers and returns the index of a given element. Use Array.prototype.findIndex() to implement the function.

Write a JavaScript function to find the index of an item in an array using Array.prototype.findIndex().

Write a function that replaces the first occurrence of a specific string in a given string.

Implement various functionalities using Array.prototype.slice() method

Create a function that takes a date and a year and sets the date's UTC full year to the provided year.

Given a sentence, split it into an array of words using the String.prototype.split() method.

Create a function that uses the copyWithin method to replace specified elements within an array.

Create a function that searches for the last index of a substring in an array using Array.prototype.lastIndexOf().

Create a program that classifies music genres based on certain audio features

Write a function that takes a string and a substring as arguments, and finds the last occurrence of the substring in the string. If the substring is not found, return -1.

Implement a function that returns true if a given string starts with a specific substring.

Write a function that takes a string and returns it in lowercase using the toLocaleLowerCase() method.

Combine two arrays into a single array using the Array.prototype.concat() method

Write a function that converts a given string to uppercase

Write a function that takes a date object and a number of seconds and returns a new date object with the seconds set to the provided value. Example input: setSeconds(new Date('2022-10-10T10:10:10'), 30) Expected output: new Date('2022-10-10T10:10:30')

Write a function that takes a string and regular expression as inputs, and returns an array of all matches found using the String.matchAll() method.

Create a function that normalizes a string using String.prototype.normalize method.

Create an Inventory Management System that allows users to add, remove and update items in the inventory.

Replace all vowels in a string with a '-'.

Create a function that returns the current minutes.

In this kata, you will be working with the String.prototype.toLocaleUpperCase() method to convert a string to uppercase according to the user's locale.

Create a function that accepts a string and a target length. If the length of the string is less than the target length, pad the string with spaces at the beginning until the target length is reached. If the string length is greater than or equal to the target length, return the original string.

Create a function that takes an array as input and returns a new array with the elements in reversed order.

Write a function that can take in a list of numbers and precision cut them to a desired number of decimal places.

Create a function that takes a start time and an event duration and returns the end time of the event, using the Date.prototype.setHours() method to set the hours of the start time.

Write a function that takes a string and returns all its substrings of length 3 or greater. You must use String.prototype.slice() to achieve this.

Implement a function that removes leading and trailing whitespace from a string using the String.prototype.trim() method.

Write a function that takes two arrays as arguments and concatenates them into a new array using the Array.prototype.concat() method.