Library

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 returns the nth number in the Fibonacci sequence using recursion.

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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 as parameters. The function should return the string repeated `n` times, where n is the number passed as parameter.

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.

Converts a given date to a time string

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.

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

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 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 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 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.

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

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

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

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

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

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

Given a date, return the UTC date.

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.

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

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

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.

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.

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

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.

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.

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

Create a function that returns the current minutes.

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

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

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.

Implement normalize method to format a string removing all the accents

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

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

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

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

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

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

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

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

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.

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

Write a function that converts a given string to uppercase

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.

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

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

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

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

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 program that classifies music genres based on certain audio features

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

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()

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

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

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

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

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

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.

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

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 in two parameters, a string and a substring, and checks if the string includes the substring. Return a boolean value.

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

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 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.

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

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