Library

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

Write a function that takes in a string and uses precision cutting to remove all occurrences of the letter 'e'. Return the resulting string.

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

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.

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

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 returns the character at the specified index of a given string.

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

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 replaces all instances of a given substring with another string within a larger string using String.prototype.replaceAll() 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().

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.

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

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

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.

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

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 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().

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

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

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 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.

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

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

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 returns an array of char codes from a string

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

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.

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

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

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

Create a function that normalizes a string using String.prototype.normalize method.

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

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 returns the nth number in the Fibonacci sequence using recursion.

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

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

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

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

Create a function that takes two strings as input and concatenates them using the String.prototype.concat() method.

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

Write a function that converts a given string to uppercase

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

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.

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

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

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

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

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.

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

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.

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

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 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 string and removes any trailing whitespace at the end of it using String.prototype.trimEnd().

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

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

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.

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.

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

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

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.

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

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

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

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.

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

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

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 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 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 sorts an array of strings in alphabetical order using String.prototype.localeCompare()

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

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

Create a function that checks if a given string ends with a specified suffix.

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

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

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

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.

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

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

Converts a given date to a time string