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

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

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

Create a function that sorts an array of strings in alphabetical order using String.prototype.localeCompare()

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.

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

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

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

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

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

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 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.

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

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

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

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 an array of matched patterns using String.prototype.matchAll().

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

Convert a string to an array of Unicode code points using 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.

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

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

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.

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

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

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

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

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

Given an array of objects, group the objects based on a specific key and return a map object.

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

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

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

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.

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

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.

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.

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

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 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.

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.

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

Implement normalize method to format a string removing all the accents

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

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

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

This kata focuses on using String.prototype.indexOf() 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 whether a given string ends with the specified suffix or not.

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 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 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 result of a string match with a given pattern.

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

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

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

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

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

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 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 replaces all occurrences of a substring with a new string.

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