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

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

Write a function that takes a string and a substring, and returns the index of the first occurrence of the substring in the string. If the substring is not found in the string, return -1.

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

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

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

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

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

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

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

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

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

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.

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

Write a function that uses recursion to calculate the factorial of a given positive integer.

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

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

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

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.

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 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.

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

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

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

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

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.

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 as input and returns a new array with the elements in reversed order.

Write a function that normalizes a string using String.prototype.normalize().

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

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

Create a function that transforms a given string to uppercase, using String.prototype.toLocaleUpperCase()

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

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 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.

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 concatenates two strings using the String.prototype.concat() method.

Write a function that converts a given string to uppercase

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

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

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

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.

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

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

Create a function that takes two strings as input and concatenates them using the String.prototype.concat() method.

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

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

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

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

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

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')

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

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

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

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.

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

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

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

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

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 checks if a given string has a unicode character code point greater than or equal to 128. Use the 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.

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

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

Converts a given date to a time string

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

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

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

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

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

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

Create a function that takes a string and a number as arguments, and pads the string on the right side with spaces until the string reaches the desired length.

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

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

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

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 normalizes a string using String.prototype.normalize method.

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

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

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

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 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.

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 checks if a given string ends with a specified suffix.

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

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.

Implement a function that returns the current month from Date object using Date.prototype.getMonth()

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

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

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

Write a function that takes a date and returns the year in the hh:mm:ss format.

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.