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

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

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

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

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.

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

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

Write a function that extracts a character from a string given an index using String.prototype.charAt()

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

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

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

Create a function that returns the current minutes.

Implement a function that concatenates a given string 'n' times using the String.prototype.repeat() 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 can take in a list of numbers and precision cut them to a desired number of decimal places.

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.

Implement a function that checks if all elements from an array are included in a given Set using the built-in Set.prototype.has() 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 checks if a given string ends with a specified suffix.

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

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

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

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 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 returns the character at the specified index of a given string.

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

Create a function that repeats a given string n times.

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 normalizes a string using String.prototype.normalize().

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

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 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.

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

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

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

Given a date, return the UTC date.

Create a function that will return an array in a localized way using the toLocaleString method.

Create a function that receives a string and normalizes it using the String.prototype.normalize() method. Apply the NFC normalization form.

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

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.

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.

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.

Create a function that receives a string and a number as parameters. The function should return the string repeated `n` times, where n is the number passed as parameter.

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

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

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

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

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

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

Write a function that takes a date object and a number representing the desired month, and sets the month of the date to the given month.

Write a function that converts a given string to uppercase

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

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

Write a function that returns the value of a given string using the String.prototype.valueOf() 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 finds the last index of a given element in an array using the Array.prototype.findLastIndex 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.

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 Stock Advisor that recommends which stocks to buy based on certain parameters.

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

Write a function that returns a substring of a given string, starting at a specified index and ending before a specified index.

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

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

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

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.

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

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

Implement a function that replaces all instances of a specified substring in a given string.

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

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

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 an array as input and returns an array of the keys of the given array using Array.prototype.keys() method.

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 removes any trailing whitespace at the end of it using String.prototype.trimEnd().

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

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

Create a function that takes a string as input and returns the same string in uppercase letters using the `toString()` method of the String object.

A kata that requires the student to use String.prototype.split() to split a given string into substrings and perform a specified operation on them.

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

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.

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

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.

Create a function that replaces all occurrences of a substring with a new string.

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

Create a function that takes a string and a number, and repeats the string the given number of times.

Create a function that greets the user depending on the current hour of the day.

Create a function that receives a string and a regular expression pattern and returns an array of all the occurrences of the pattern in the string using String.prototype.matchAll().

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

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

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 replaces the first occurrence of a specific string in a given string.

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 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 the Array.prototype.unshift() method without using built-in functions

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().

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

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.