Library

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.

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

Given an array of numbers and a start index, remove a certain number of elements from the array and replace them with new elements.

Write a function that takes a Date object and returns the date formatted in the user's local format using the toLocaleDateString() method.

Create a function that takes in a string and uses String.prototype.match() to find all occurrences of a pattern within the string.

Write a function that takes a Date object and returns a string representing the time portion of the date in the current time zone using the toLocaleTimeString() method. The function should also take an optional argument specifying the locale to use.

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().

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

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

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

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

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 returns the value of a given string using the String.prototype.valueOf() method.

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.

Write a function that accepts a string and a number as arguments, then returns the character at that position in the string. Use String.prototype.charAt() for this exercise.

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

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 replaces all occurrences of a substring with a new string.

Complete the functions to find the index of an element in an array using Array.prototype.indexOf().

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

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

Create a function that takes a string and returns a new string that is a slice of the original string. The function should take two arguments, start and end, which represent the starting and ending indices of the slice.

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.

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

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

Implement a function that uses String's padStart method to add leading zeros to a number string to ensure it always has a minimum length

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

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

Implement a function that sets the milliseconds of a given date object to a specified value.

Create a function that takes a string and returns an array of the char codes for each character in the string

Write a function that checks whether a given string ends with the specified suffix or not.

Create a function that repeats a given string n times.

Write a function that takes a date string as input and converts it to a UTC date string format.

Create a function that returns the month of a Date object in UTC time zone.

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

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')

Convert a string to an array of Unicode code points using String.prototype.codePointAt() method.

Write a function that uses the String.prototype.trimStart() method to remove any whitespace characters from the beginning of a given string.

Convert a string to uppercase using String.prototype.toUpperCase();

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

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

Create a function that takes a Date object and returns a JSON string of the date in ISO format.

Create a function that takes a date and a year as arguments and returns a new date with the year set to the specified value using Date.prototype.setFullYear().

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.

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.

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

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

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

Write a function that converts a given string to its string representation using the toString() method.

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

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

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

Given two arrays, join them to create a new array.

Create a function that takes in a string and checks if it starts with a given substring. Return a boolean indicating whether or not the string starts with the given substring.

Write a function that returns the nth number in the Fibonacci sequence using recursion.

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

Create a function that returns the current minutes.

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 checks if a given string ends with a specified suffix.

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

Create a function that replaces all instances of a given substring with another string within a larger string using String.prototype.replaceAll() method.

Write a function that takes an array and a value and pushes the value to the end of the array using Array.prototype.push().

Create a function that takes two parameters: a string and a target substring, and returns the index of the first occurrence of the target substring in the string. If the target substring is not found, return -1.

Write a function that takes in a string and uses precision cutting to remove all occurrences of the letter 'e'. Return the resulting string.

Create a function that concatenates two strings using the String.prototype.concat() method. The function should take two string parameters and return the concatenated string.

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.

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

Write a function that converts a given string to uppercase

Given a date, return the UTC date.

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

Create a function that takes an array as input and returns an array of the keys of the given array using Array.prototype.keys() method.

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.

Write a function that finds the last index of a given element in an array using the Array.prototype.findLastIndex method.

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

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

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.

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

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

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.

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

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

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.

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

Implement a function that uses String.prototype.trimEnd() to trim whitespace at the end of a string.

Write a function that takes a string and a search term and returns the index of the first occurrence of the search term in the given string. If the search term is not present in the string, return -1.

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

Write a function that takes in a date and returns the seconds within the minute in UTC time.

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

Implement a function that takes a Date object as input and returns a formatted string

Create a function that takes in an array of music tracks and returns an object with the count of each genre in the array

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

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.

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

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

Write a function that takes a string as input and splits it into an array of words using String.prototype.split(). Then, join the array back into a string using Array.prototype.join(). Finally, return the new string with a different delimiter separating each word.

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.

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

Implement a function that takes a Date object and a number representing minutes and sets the UTC minutes of the Date object to the provided value. The function should return the updated Date object.

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