Library

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 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 Date object and returns the date formatted in the user's local format using the toLocaleDateString() 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.

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

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

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

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

Write a function that takes in a string and uses precision cutting to remove all occurrences of the letter 'e'. Return the resulting 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 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 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 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 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 takes a date and a year and sets the date's UTC full year to the provided year.

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

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

Write a function that normalizes a string using String.prototype.normalize().

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

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

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

Create a function that accepts a Set and a value to remove, and returns the updated Set after deleting the value.

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

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.

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

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

Converts a given date to a time 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.

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

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

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

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

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

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

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

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

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.

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

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

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 checks if a given string ends with a specified suffix.

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

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

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

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

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

Create a function that returns the current minutes.

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 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 returns an array of values of an array using the Array.prototype.values() method.

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

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

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

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

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 takes an integer n and returns the nth Fibonacci number using recursion.

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

Create a function that normalizes a string using String.prototype.normalize 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 checks whether a given string ends with the specified suffix or not.

Implement normalize method to format a string removing all the accents

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

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

Create a function that determines if two strings are anagrams of each other.

Create a function that takes a string as input and returns the string in all lowercase letters.

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

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

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 takes a Date object as input and returns a formatted string

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

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 program that classifies music genres based on certain audio features

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

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

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 function that repeats a given string n times.

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

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

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

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

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.

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

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.

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 counts the number of seconds in a given timestamp

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

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

Write a function that converts a given string to its string representation using the toString() 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 takes two arrays as arguments and concatenates them into a new array using the Array.prototype.concat() method.

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

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