Library

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.

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 the Array.prototype.with() method that returns a new array with the elements from the original array and the added elements.

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.

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

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

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

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 returns the current year using Date's built-in getFullYear method

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 repeats a given string n times.

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

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.

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

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

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

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

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

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.

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

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

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 greets the user depending on the current hour of the day.

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().

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

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

Write a function that converts a given string to uppercase

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.

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 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 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 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.

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

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

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.

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

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

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 normalizes a string using String.prototype.normalize().

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

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

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 checks if a given variable is an array. If it is an array, return true, otherwise return false.

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().

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

Create a function that takes a date and a year and sets the date's UTC full year to the provided year.

Sort an array of words based on their alphabetical order using String.prototype.localeCompare() method.

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

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.

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

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

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

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

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

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

Create a function that uses the copyWithin method to replace specified elements within an array.

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

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

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

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

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

Create a function that takes two strings as input and concatenates them using the String.prototype.concat() 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 takes an array and reverse its order in place.

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

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.

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

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

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.

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

Create a function that returns an array of values of an array using the Array.prototype.values() method.

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

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

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

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

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

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

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

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 uses String's padStart method to add leading zeros to a number string to ensure it always has a minimum length

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

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

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')

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

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

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

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 checks if every element in an array satisfies a given condition.

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.