JavaScript fundamental (ES6) - Exercises, Practice, Solution
This resource offers a total of 590 more JavaScript fundamental problems for practice. It includes 118 main exercises, each accompanied by solutions, detailed explanations, and four related problems.
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151. Run Function in Web Worker
Write a JavaScript program to run a function in a separate thread using a Web Worker. This allows long running functions to not block the UI.
152. Round Number to Digits
Write a JavaScript program to round a number to a specified amount of digits.
153. Reverse Characters in String
Write a JavaScript program to reverse the order of characters in the string.
154. Object from Properties Failing Function
Write a JavaScript program to create an object composed of the properties the given function returns false for. The function is invoked with two arguments: (value and key).
155. Filter Where Predicate is False
Write a JavaScript program that takes a predicate and an array, like Array.filter(), but only keeps x if pred(x) returns false.
156. Array Successive Reduce Values
Write a JavaScript program to apply a function against an accumulator and each element in the array (from left to right), returning an array of successively reduced values.
157. Redirect to URL
Write a JavaScript program to redirect to a specified URL.
158. Rearrange Function Arguments
Write a JavaScript program to create a function that invokes the provided function with its arguments arranged according to the specified indexes.
159. Read File Lines into Array
Write a JavaScript program to get an array of lines from the specified file.
160. Mutate Array with Filter and Iterator
Write a JavaScript program to mutate the original array to filter out the values specified, based on a given iterator function.
161. Filter and Return Removed Elements
Write a JavaScript program to mutate the original array to filter out the values specified. Returns the removed elements.
162. Async to Promise Conversion
Write a JavaScript program to convert an asynchronous function to return a promise.
163. Bytes to Human-Readable String
Write a JavaScript program to convert a number in bytes to a human-readable string.
164. Singular or Plural Form
Write a JavaScript program that returns the singular or plural form of the word based on the input number.
165. Left-to-Right Function Composition
Write a JavaScript program to perform left-to-right function composition.
166. Async Left-to-Right Composition
Write a JavaScript program to perform left-to-right function composition for asynchronous functions.
167. Count Less-Than-or-Equal Numbers
Write a JavaScript program to calculate how many numbers in the given array are less than or equal to the given value. This is done using the percentile formula.
168. Group Elements by Predicate Truthiness
Write a JavaScript program to group the elements into two arrays, depending on the provided function's truthiness for each element.
169. Function with Appended Partials
Write a JavaScript program to create a function that invokes fn with partials appended to the arguments it receives.
170. Function with Prepended Partials
Write a JavaScript program to create a function that invokes fn with partials prepended to the arguments it receives.
171. Parse Cookie Header to Object
Write a JavaScript program to parse an HTTP Cookie header string and return an object of all cookie name-value pairs.
172. Function with Transformed Arguments
Write a JavaScript program to create a function that invokes the provided function with its arguments transformed.
173. Get nth Array Element
Write a JavaScript program to get the nth element of a given array of elements.
174. Convert NodeList to Array
Write a JavaScript program to convert a NodeList into an array.
175. Index of Fastest Function
Write a JavaScript program to get the index of the function in an array of functions which executed the fastest.
176. n Minimum Elements in Array
Write a JavaScript program to get the n minimum elements from the provided array. If n is greater than or equal to the provided array's length, return the original array (sorted in ascending order).
177. Minimum Value After Mapping
Write a JavaScript program to get the minimum value of an array, after mapping each element to a value using the provided function.
178. Merge Objects into New Object
Write a JavaScript program to create a new object from the combination of two or more objects.
179. Object Comparison by Function
Write a JavaScript program to compare two objects to determine if the first contains equivalent property values to the second one. This is based on a provided function.
180. Object with Lowercase Keys
Write a JavaScript program to create an object from the specified object, where all keys are in lowercase.
181. Get Last Array Element
Write a JavaScript program to get the last element from an given array.
182. Join Array with End Separator
Write a JavaScript program to join all elements of an array into a string and return this string. Use a separator and an end separator.
183. Check Valid JSON
Write a JavaScript program to check if the provided argument is valid JSON.
184. Check String Uppercase
Write a JavaScript program to check if a given string is upper case or not.
185. Check If Undefined
Write a JavaScript program that returns true if the specified value is undefined, false otherwise.
186. Check If Symbol
Write a JavaScript program to check if the given argument is a symbol.
187. Check If String
Write a JavaScript program to check if the given argument is a string.
188. Array Sort Order
Write a JavaScript program that returns 1 if the array is sorted in ascending order. It returns -1 if it is sorted in descending order or 0 if it is not sorted.
189. Check If Looks Like Promise
Write a JavaScript program that returns true if an object looks like a Promise, false otherwise.
190. Check If Primitive
Write a JavaScript program to return a boolean determining if the passed value is primitive or not.
191. Check If Prime Number
Write a JavaScript program to check if the provided integer is a prime number or is not.
192. Check If Object by Constructor
Write a JavaScript program to check if the provided value is an object created by the Object constructor.
193. Check If Object-Like
Write a JavaScript program to check if a value is object-like. Check if the provided value is not null and its typeof is equal to 'object'.
194. Check If Object
Write a JavaScript program to get a boolean determining if the passed value is an object or not.
195. Check If Number
Write a JavaScript program to check if a given argument is a number.
196. Check If Null
Write a JavaScript program that will return true if the specified value is null, false otherwise.
197. Check String Lowercase
Write a JavaScript program to check if a string is lower case or not.
198. Check If Function
Write a JavaScript program to check if the given argument is a function.
199. Check If Even Number
Write a JavaScript program that returns true if the given number is even, false otherwise.
200. Check If Empty Object or Collection
Write a JavaScript program that returns true if a value is an empty object, collection, map or set. It has no enumerable properties or is of any type not considered a collection.
201. Check Divisibility
Write a JavaScript program to check if the first numerical argument is divisible by the second one.
202. Check Even Number
Write a JavaScript program to check if a given number is even or not.
203. Check Browser Environment
Write a JavaScript program to determine if the current runtime environment is a browser. This is so that front-end modules can run on the server (Node) without errors.
204. Check Native Boolean
Write a JavaScript program that checks if the given argument is a native Boolean element.
205. Check If Array
Write a JavaScript program to check if the provided argument is an array (i.e. iterable).
206. Check Anagram
Write a JavaScript program to check if a given string is an anagram of another string (case-insensitive, ignores spaces, punctuation and special characters).
207. Check Absolute URL
Write a JavaScript program that returns true if the given string is an absolute URL, false otherwise.
208. Check Specified Type
Write a JavaScript program to check if the provided value is of the specified type.
209. Common Elements by Comparator
Write a JavaScript program to get a list of elements in both arrays, using a provided comparator function.
210. Common Elements After Mapping
Write a JavaScript program to get a list of elements in both arrays, after applying the provided function to each array element of both.
211. Common Elements in Arrays
Write a JavaScript program to get a list of elements that exist in both arrays.
212. n-Dimensional Array
Write a JavaScript program to create a n-dimensional array with a given value.
213. Initialize and Fill Array
Write a JavaScript program to initialize and fill an array with the specified values.
214. Range Array in Reverse
Write a JavaScript program to initialize an array containing the numbers in the specified range (in reverse) where start and end are inclusive of their common difference step.
215. All Elements Except Last
Write a JavaScript program to get all the elements of an array except the last one.
216. Indices of Value in Array
Write a JavaScript program to get all val indices in an array. If val never occurs, return [].
217. Number in Range
Write a JavaScript program to check if the given number falls within the given range.
218. Function Execution Frequency (Hz)
Write a JavaScript program to get the number of times a function executed per second. HZ is the unit for hertz, the unit of frequency defined as one cycle per second.
219. Hamming Distance
Write a JavaScript program to calculate the Hamming distance between two values.
220. Get Native Type of Value
Write a JavaScript program to get the native type of a value. Returns the lowercased constructor name of value, "undefined" or "null" if value is undefined or null.
221. Time from Date Object
Write a JavaScript program to get a string like HH:MM:SS from a Date object.
222. Range Array with Ratio Step
Write a JavaScript program that initializes an array containing the numbers in the specified range. This is where start and end are inclusive and the ratio between the two terms is step. Returns an error if step equals 1.
223. Greatest Common Divisor
Write a JavaScript program to calculate the greatest common divisor between two or more numbers/arrays.
224. Remove HTML/XML Tags
Write a JavaScript program to remove HTML/XML tags from strings.
225. Standard Deviation
Write a JavaScript program to get the standard deviation of an array of numbers.
226. n Random Unique Elements
Write a JavaScript program to get n random elements with unique keys from an array up to the size of the array.
227. Remove Elements by Function
Write a JavaScript program to remove elements from an array for which the given function returns false.
228. Log Function Name
Write a JavaScript program to log the name of a function.
229. Camelcase to String
Write a JavaScript program to convert a string from camelcase.
230. Milliseconds to Human Format
Write a JavaScript program to generate the human-readable format in the given number of milliseconds.
231. Iterate Object Properties in Reverse
Write a JavaScript program to iterate over all the properties of an object in reverse, running a callback for each one.
232. Move First Argument Last
Write a JavaScript program that takes a function as an argument, then makes the first argument the last.
233. Flatten Object Keys as Paths
Write a JavaScript program to flatten an object with the paths for keys.
234. Flatten Array to Depth
Write a JavaScript program to flatten a given array to the specified depth.
235. Last Key Satisfying Condition
Write a JavaScript program to get the last key that satisfies the provided testing function, otherwise undefined is returned.
236. First Key Satisfying Condition
Write a JavaScript program to get the first key that satisfies the provided testing function. Otherwise return undefined.
237. Fibonacci Sequence
Write a JavaScript program to generate an array containing the Fibonacci sequence, up to the nth term.
238. Factorial of Number
Write a JavaScript program to calculate the factorial of a number.
239. Escape String for Regex
Write a JavaScript program to escape a string to use in a regular expression.
240. Check Parent Contains Child
Write a JavaScript program that returns true if the parent element contains the child element, false otherwise.
241. Remove Elements Until Condition
Write a JavaScript program to remove elements from an array until the passed function returns true. Returns the remaining elements in the array.
242. Remove Elements from End Until Condition
Write a JavaScript program to remove elements from the end of an array until the passed function returns true. Returns the remaining elements of the array.
243. Distance Between Points
Write a JavaScript program to get the distance between two given points.
244. Difference Between Arrays
Write a JavaScript program to get the difference between two given arrays.
245. Invoke Function After Delay
Write a JavaScript program that invokes the provided function after a few milliseconds.
246. Degrees to Radians
Write a JavaScript program to convert angles from degrees to radians.
247. Assign Defaults to Object
Write a JavaScript program that assigns default values to all undefined properties in an object.
248. Deep Flatten Array
Write a JavaScript program to deep flatten an array.
249. Get Current URL
Write a JavaScript program to get the current URL.
250. Create Element from String
Write a JavaScript program to create an element from a string (without appending it to the document).
251. Write JSON to File
Write a JavaScript program to write a JSON object to a file.
252. RGB to Color Code
Write a JavaScript program to convert the values of RGB components to a color code.
253. Generate UUID (Browser)
Write a JavaScript program to generate a UUID in a browser.
254. Generate UUID (Node.js)
Write a JavaScript program to generate a UUID in Node.JS. Use crypto API to generate a UUID, compliant with RFC4122 version 4.
255. Predicate True for Any
Write a JavaScript program that returns true if the provided predicate function returns true for at least one element in a collection, false otherwise.
256. Approximate Equality Check
Write a JavaScript program to check if two given numbers are approximately equal to each other.
257. 2D Array to CSV
Write a JavaScript program to convert a 2D array to a comma-separated value (CSV) string.
258. Limit Function Arguments
Write a JavaScript program to create a function that accepts up to n arguments, ignoring any additional arguments.
259. Decode Base-64 String
Write a JavaScript program to decode a string of data encoded using base-64 encoding.
260. Binomial Coefficient
Write a JavaScript program to evaluate the binomial coefficients of two integers n and k.
261. Check Page Bottom Visible
Write a JavaScript program that returns true if the page bottom is visible, false otherwise.
262. Encode String to Base-64
Write a JavaScript program to create a base-64 encoded ASCII string from a String object in which each character in the string is treated as a byte of binary data.
263. Capitalize First Letter
Write a JavaScript program to capitalize the first letter of a string.
264. Capitalize First Letters of Words
Write a JavaScript program to capitalize the first letter of every word in a string.
265. Chunk Array
Write a JavaScript program to chunk an array into smaller arrays of a specified size.
266. Clamp Number in Range
Write a JavaScript program to clamp a number within the inclusive range specified by the given boundary values a and b.
267. Midpoint Between Points
Write a JavaScript program to calculate the midpoint between two pairs of points.
268. Index of Array Item in Loop
Write a JavaScript program to find the index of an array item in a for loop.
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