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

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

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.

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

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

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

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

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

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

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.

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

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 counts the number of seconds in a given timestamp

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.

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

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

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

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

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

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

Write a function that converts a given string to uppercase

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.

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

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

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.

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

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

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 sorts an array of strings in alphabetical order using String.prototype.localeCompare()

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

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

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.

Write a function that takes in a string and a target substring, and returns the index at which the target substring is first found. If the target substring is not found in the string, return -1. Use the built-in JavaScript method `indexOf()` to solve the problem.

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

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

Create a function that returns the current minutes.

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

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 in a date and returns the seconds within the minute in UTC time.

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 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.

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

Converts a given date to a time string

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.

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

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

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

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 returns an array of values of an array using the Array.prototype.values() 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().

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

Write a function that checks if a given string includes a specific substring. Use String.prototype.includes() 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 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 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 it in lowercase using the toLocaleLowerCase() method.

Create a function that concatenates two strings using the String.prototype.concat() method.

Given a date, return the UTC date.

Create a function that takes two parameters: a string and a regular expression. The function should return an array of all matches found in the string using the regular expression.

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

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

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 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.

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

Implement normalize method to format a string removing all the accents

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

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

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

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.

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.

Create a function that uses Array.prototype.every() to check if all the elements in an array meet a certain condition.

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

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.

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

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

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

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

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

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

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

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

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

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

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

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().

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