Library

Write a function that uses the Date.prototype.getDay() method to determine the day of the week for a given date object.

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

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

Converts a given date to a time string

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

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

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.

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

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 determines if two strings are anagrams of each other.

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 two strings as input and concatenates them using the String.prototype.concat() method.

Create a function that returns the current minutes.

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

Create a function that slices a string based on a given start and end indexes

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

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

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

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

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

Write a function that takes an array and a value as arguments and returns the index of the last occurrence of that value in the array using Array.prototype.lastIndexOf(). If the value is not found, return -1.

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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 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.

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

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

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

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

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

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

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

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

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

Write a function that converts a given string to uppercase

Given a date, return the UTC date.

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

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

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.

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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 concatenates a given string 'n' times using the String.prototype.repeat() 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.

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

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

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

This kata focuses on using String.prototype.indexOf() 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 replaces all instances of a given substring with another string within a larger string using String.prototype.replaceAll() method.

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

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

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

Implement normalize method to format a string removing all the accents

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