Library

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

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

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

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

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

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

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

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

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

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

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 checks if a given string has a unicode character code point greater than or equal to 128. Use the String.prototype.codePointAt() method.

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

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

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

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

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

Create a function that repeats a given string n times.

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

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

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 a date string as input and converts it to a UTC date string format.

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

Write a function that returns the value of a given string using the String.prototype.valueOf() 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 receives a string and normalizes it using the String.prototype.normalize() method. Apply the NFC normalization form.

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 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.

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 true if a given string starts with a specific substring.

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

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

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

Write a function that converts a given string to uppercase

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

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

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

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 a date and a year and sets the date's UTC full year to the provided year.

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.

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

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

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

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

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

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

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.

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.

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

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

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

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.

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

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

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 returns the current month from Date object using Date.prototype.getMonth()

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

Given a date, return the UTC date.

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

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

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 a string and returns an array of code points for each character in the string using String.prototype.codePointAt() method.

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

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

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

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

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

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

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.

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.

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

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.

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

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

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 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.

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.

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

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.

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

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

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

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

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

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

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

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

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