Library

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 and pads that string with a specified character until it reaches the given length.

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.

Sort an array of words based on their alphabetical order using String.prototype.localeCompare() 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 counts the number of seconds in a given timestamp

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

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

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.

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

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

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

Implement a function that uses String.prototype.trimEnd() to trim whitespace at the end of a string.

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 slices a string based on a given start and end indexes

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

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

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

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 converts a given string to uppercase

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

Implement normalize method to format a string removing all the accents

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

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

Create a function that repeats a given string n times.

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.

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

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

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

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

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

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

Create a function that takes in a string with extra white space at the beginning and end of the string, and returns a new string with that white space removed. Use String.prototype.trim().

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

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

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

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

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().

Converts a given date to a time string

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

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

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

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.

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

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

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

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 takes a Date object as input and returns a formatted string

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

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

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.

Create a function that returns the current minutes.

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

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

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

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

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

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

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 concatenates two strings using the String.prototype.concat() method. The function should take two string parameters and return the concatenated string.

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

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

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

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

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

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

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

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

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

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 a string as input and returns it in lower case.

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

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

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.

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

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