Library
easy
Date UTC Minutes Setter
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.
medium
Music genre classification
Create a program that classifies music genres based on certain audio features
easy
String.lastIndexOf() Kata
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.
medium
String MatchAll Kata
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.
easy
Array Index Of Kata
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.
easy
String valueOf() Kata
Write a function that returns the value of a given string using the String.prototype.valueOf() method.
easy
Date.toLocaleDateString() Kata
Write a function that takes a Date object and returns the date formatted in the user's local format using the toLocaleDateString() method.
medium
Array Index Finder
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.
easy
String toString()
Write a function that converts a given string to its string representation using the toString() method.
medium
Slice and Dice
Use Array.prototype.slice() to solve the following tasks.
easy
Reverse Array
Create a function that takes an array and reverse its order in place.
easy
Repeat String
Create a function that repeats a given string n times.
easy
UTC Date Converter
Write a function that takes a date string as input and converts it to a UTC date string format.
easy
CharAt Kata
Implement a function that returns the character at the specified index of a given string.
easy
Date Prototype Get Date
Create a function that returns the current date as a number (1-31).
easy
Clearing unused items from Set
Implement a function that removes all unused items in a Set collection
easy
Sum of numbers using reduceRight()
Write a function that takes an array of numbers and returns their sum, using Array.prototype.reduceRight().
easy
Code Point At
Convert a string to an array of Unicode code points using String.prototype.codePointAt() method.
easy
String to Uppercase
Write a function that converts a given string to uppercase
easy
Normalize String Kata
Write a function that normalizes a string using String.prototype.normalize().
easy
Find the First Occurrence of a Substring in a String
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.
easy
Concatenation Kata
Write a function that concatenates two strings using the String.prototype.concat() method.
medium
Date toLocaleTimeString() kata
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.
easy
Last Index Of Substring Kata
Create a function that searches for the last index of a substring in an array using Array.prototype.lastIndexOf().
easy
Find the position of a substring using indexOf()
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.
easy
Word sorting
Sort an array of words based on their alphabetical order using String.prototype.localeCompare() method.
medium
String Replace All Kata
Create a function that replaces all instances of a given substring with another string within a larger string using String.prototype.replaceAll() method.
medium
Recursive Fibonacci
Write a function that takes an integer n and returns the nth Fibonacci number using recursion.
easy
Set Delete Kata
Create a function that accepts a Set and a value to remove, and returns the updated Set after deleting the value.
medium
Array with() method
Implement the Array.prototype.with() method that returns a new array with the elements from the original array and the added elements.
medium
Stock Advisor
Create a Stock Advisor that recommends which stocks to buy based on certain parameters.
medium
Inventory Management System
Create an Inventory Management System that allows users to add, remove and update items in the inventory.
easy
UTC Date
Given a date, return the UTC date.
easy
String Slice Kata
Create a function that slices a string based on a given start and end indexes
easy
Convert Date to JSON String
Create a function that takes a Date object and returns a JSON string of the date in ISO format.
easy
Joining Arrays
Given two arrays, join them to create a new array.
easy
String Concatenation Kata
Create a function that concatenates two strings using the String.prototype.concat() method.
easy
Every Check
Write a function that checks if every element in an array satisfies a given condition.
easy
Array Concat Kata
Combine two arrays into a single array using the Array.prototype.concat() method
medium
Array Entries Kata
Create a function that uses Array.prototype.entries() to iterate over an array and perform some operations.
medium
Array Grouping Kata
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.
easy
Array toLocaleString Kata
Create a function that will return an array in a localized way using the toLocaleString method.
easy
String Repeat Kata
Implement a function that concatenates a given string 'n' times using the String.prototype.repeat() method.
easy
String repeat Kata
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.
medium
Slice Challenge
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.
easy
Array to String Conversion
Convert an array to a string with comma-separated values. The input array can contain numbers, strings, objects, or arrays.
easy
Joining Arrays Kata
Write a function that joins two arrays into a single string using Array.prototype.join() method.
medium
MatchAll Kata
Write a function that takes a string and returns an array of matched patterns using String.prototype.matchAll().
easy
Lowercase Kata
Create a function that takes a string as input and returns the string in all lowercase letters.
easy
Get UTC Seconds
Write a function that takes in a date and returns the seconds within the minute in UTC time.
medium
Array Slice and Splice
Given an array of numbers and a start index, remove a certain number of elements from the array and replace them with new elements.
easy
Trimming White Space at End of String
Create a function that removes white space at the end of a given string using String.prototype.trimEnd().
easy
Match String Pattern
Write a function that returns the result of a string match with a given pattern.
easy
Array Type Check
Write a function that checks if a given variable is an array. If it is an array, return true, otherwise return false.
easy
UTC Month Setter
Create a function that sets the UTC month of a given date object.
easy
Normalize String Kata
Create a function that normalizes a string using String.prototype.normalize method.
easy
Find Last Index Kata
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.
easy
String Repeat Kata
Create a function that receives a string and a number n, the function should return the string repeated n times.
medium
Recursive Factorial Function
Write a function that uses recursion to calculate the factorial of a given positive integer.
easy
String PadStart Kata
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
easy
Set Milliseconds Kata
Implement a function that sets the milliseconds of a given date object to a specified value.
easy
Date Month Kata
Implement a function that returns the current month from Date object using Date.prototype.getMonth()
easy
String.charAt() Kata
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.
easy
String includes
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.
easy
String code point kata
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.
easy
Current Minutes
Create a function that returns the current minutes.
medium
Find Last Exercise
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.
easy
Pad Start Kata
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.
easy
String StartsWith Kata
Implement a function that returns true if a given string starts with a specific substring.
medium
Array Grouping Kata
Implement a function that groups the elements of an array based on a given predicate function.
easy
String trimStart() Method
Write a function that uses the String.prototype.trimStart() method to remove any whitespace characters from the beginning of a given string.
easy
Uppercase String Transformation
Create a function that transforms a given string to uppercase, using String.prototype.toLocaleUpperCase()
easy
Date.now() Kata
Complete the functions provided to properly utilize the Date.now() method.
easy
String Slice Kata
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.
easy
Set Event Start Time
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.
easy
Array Push Kata
Write a function that takes an array and a value and pushes the value to the end of the array using Array.prototype.push().
easy
Array Includes Kata
Write a function that checks if an element is present in an array using Array.prototype.includes() method.
easy
Array Filling Kata
Fill arrays with specific values using Array.prototype.fill()
easy
String Includes Kata
Write a function that checks if a given string includes a specific substring. Use String.prototype.includes() method.
easy
Set Seconds Kata
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')
easy
String to Uppercase
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.
medium
String Match Kata
Create a function that takes in a string and uses String.prototype.match() to find all occurrences of a pattern within the string.
easy
String Search Kata
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.
easy
Match Me If You Can
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.
easy
String Trim End Kata
Implement a function that uses String.prototype.trimEnd() to trim whitespace at the end of a string.
medium
Find Last Index Kata
Write a function that finds the last index of a given element in an array using the Array.prototype.findLastIndex method.
easy
Set forEach Kata
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.
easy
Date Set UTC Seconds
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.
easy
String ReplaceAll Kata
Implement a function that replaces all instances of a specified substring in a given string.
easy
Sort names using localeCompare()
Given an array of person objects, sort them alphabetically by their last name using String.prototype.localeCompare().
medium
Array ToSpliced
Create a function that takes an array and removes a portion of the array, as specified by the arguments, and returns the removed portion.
medium
String Normalization Kata
Create a function that receives a string and normalizes it using the String.prototype.normalize() method. Apply the NFC normalization form.
easy
Split and Join String Exercise
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.
easy
Array Index Kata
Complete the functions to find the index of an element in an array using Array.prototype.indexOf().
medium
Airline Overbooking
Implement an algorithm that manages the overbooking of an airline flight.
easy
String Concatenation Kata
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.
easy
Last Occurrence of a Substring in a String
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.
medium
Split String Kata
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.
easy
Date Time Conversion
Converts a given date to a time string
easy
Array.of() Exercise
Implement equations using the Array.of() method to create arrays.