JavaScript Coding Questions

As a Front-End developer, JavaScript is the core skill of everything

• 3. implement Array.prototype.flat()JavaScriptmedium24310 accepted
• 4. implement basic throttle()JavaScriptLodashmedium17876 accepted
• 16. create an Event EmitterJavaScriptmedium10689 accepted
• 2. implement curry() with placeholder supportJavaScriptmedium9271 accepted
• 32. implement `Promise.all()`JavaScriptmedium8377 accepted
• 14. Implement a general memoization function - `memo()`JavaScriptmedium8368 accepted
• 8. can you shuffle() an array?JavaScriptmedium7421 accepted
• 23. create a sum()JavaScriptmedium6562 accepted
• 7. implement debounce() with leading & trailing optionJavaScriptLodashmedium6425 accepted
• 9. decode messageJavaScriptmedium6303 accepted
• 5. implement throttle() with leading & trailing optionJavaScriptLodashmedium6175 accepted
• 10. first bad versionJavaScriptAlgorithmmedium6121 accepted
• 58. get DOM tree heightJavaScriptAlgorithmDOMmedium5452 accepted
• 151. implement Array.prototype.map()JavaScriptmedium5342 accepted
• 33. implement `Promise.allSettled()`JavaScriptmedium4570 accepted
• 29. implement async helper - `sequence()`JavaScriptmedium4556 accepted
• 34. implement `Promise.any()`JavaScriptmedium4398 accepted
• 64. auto-retry Promise on rejectionJavaScriptmedium4328 accepted
• 92. throttle PromisesJavaScriptmedium4018 accepted
• 113. Virtual DOM IJavaScriptAlgorithmDOMmedium3839 accepted
• 13. Implement a Queue by using StackJavaScriptAlgorithmmedium3533 accepted
• 161. toBe() or not.toBe()JavaScriptmedium3518 accepted
• 146. implement Array.prototype.reduce()JavaScriptmedium3099 accepted
• 57. create an ObservableJavaScriptmedium3095 accepted
• 104. Traverse DOM level by levelJavaScriptAlgorithmDOMmedium3031 accepted
• 68. get DOM tagsJavaScriptAlgorithmDOMmedium2974 accepted
• 30. implement async helper - `parallel()`JavaScriptmedium2926 accepted
• 20. Detect data type in JavaScriptJavaScriptmedium2906 accepted
• 67. create your own PromiseJavaScriptmedium2868 accepted
• 26. implement Object.assign()JavaScriptmedium2844 accepted
• 12. implement Immutability helperJavaScriptmedium2788 accepted
• 46. implement `_.once()`JavaScriptLodashmedium2604 accepted
• 63. create `_.cloneDeep()`JavaScriptAlgorithmLodashmedium2589 accepted
• 168. move zerosJavaScriptAlgorithmmedium2582 accepted
• 110. serialize and deserialize binary treeJavaScriptAlgorithmmedium2462 accepted
• 56. call APIs with paginationJavaScriptmedium2250 accepted
• 85. implement `_.get()`JavaScriptLodashmedium2178 accepted
• 61. create your own `Function.prototype.call`JavaScriptmedium2162 accepted
• 125. implement classNames()JavaScriptmedium2081 accepted
• 69. implement deep equal `_.isEqual()`JavaScriptLodashmedium2070 accepted
• 123. implement Promise.prototype.finally()JavaScriptmedium2027 accepted
• 103. implement Math.sqrt()JavaScriptAlgorithmmedium2009 accepted
• 83. create an intervalJavaScriptmedium1849 accepted
• 130. create LazyMan()JavaScriptmedium1742 accepted
• 173. uncompress stringJavaScriptstringalgorithmmedium1695 accepted
• 53. write your own `extends` in es5JavaScriptmedium1667 accepted
• 158. Previous Left SiblingJavaScriptDOMmedium1634 accepted
• 122. implement memoizeOne()JavaScriptmedium1582 accepted
• 131. implement _.chunk()JavaScriptLodashmedium1571 accepted
• 86. Generate Fibonacci NumberJavaScriptAlgorithmmedium1560 accepted
• 66. remove duplicates from an arrayJavaScriptAlgorithmmedium1470 accepted
• 36. create a fake timer(setTimeout)JavaScriptmedium1364 accepted
• 65. add comma to numberJavaScriptmedium1351 accepted
• 24. create a Priority Queue in JavaScriptJavaScriptAlgorithmmedium1350 accepted
• 156. implement `_.set()`JavaScriptLodashmedium1327 accepted
• 135. localStorage with expirationJavaScriptmedium1320 accepted
• 59. create a browser historyJavaScriptmedium1316 accepted
• 90. write your own `instanceof`JavaScriptmedium1265 accepted
• 152. Find Top k ElementsJavaScriptAlgorithmmedium1241 accepted
• 55. highlight keywords in HTML stringJavaScriptAlgorithmmedium1224 accepted
• 43. implement Quick SortJavaScriptAlgorithmmedium1212 accepted
• 22. implement JSON.parse()JavaScriptmedium1201 accepted
• 27. implement completeAssign() JavaScriptmedium1179 accepted
• 41. implement Merge SortJavaScriptAlgorithmmedium1163 accepted
• 101. merge identical API callsJavaScriptmedium1142 accepted
• 52. create a middleware systemJavaScriptmedium1109 accepted
• 139. implement _.partial()JavaScriptLodashmedium1092 accepted
• 95. implement String.prototype.trim()JavaScriptmedium1027 accepted
• 82. find available meeting slotsJavaScriptAlgorithmmedium1021 accepted
• 79. convert snake_case to camelCaseJavaScriptmedium1016 accepted
• 170. Generate CSS Selector for target elementJavaScriptmedium962 accepted
• 88. support negative Array index in JavaScriptJavaScriptmedium902 accepted
• 45. find the K-th largest element in an unsorted arrayJavaScriptAlgorithmmedium900 accepted
• 166. validate number stringJavaScriptAlgorithmstringmedium866 accepted
• 117. event delegationJavaScriptmedium845 accepted
• 136. find median of two sorted arrayJavaScriptAlgorithmmedium830 accepted
• 149. interpolationJavaScriptmedium807 accepted
• 111. Count palindromic substringsJavaScriptAlgorithmstringmedium751 accepted
• 177. Implement Object.groupBy()JavaScriptmedium740 accepted
• 108. Implement a Stack by using QueueJavaScriptAlgorithmmedium738 accepted
• 132. the angle between hour hand and minute hand of a clockJavaScriptmedium707 accepted
• 119. create a tokenizerJavaScriptmedium685 accepted
• 112. remove duplicate characters in a stringJavaScriptAlgorithmstringmedium639 accepted
• 134. create your own CookieJavaScriptmedium632 accepted
• 153. uglify CSS class namesJavaScriptmedium612 accepted
• 70. implement Observable.from()JavaScriptmedium602 accepted
• 172. implement `Math.clz32()`JavaScriptmedium595 accepted
• 84. create a fake timer (setInterval)JavaScriptmedium569 accepted
• 71. implement Observable SubjectJavaScriptmedium543 accepted
• 99. extract all anchor element from HTML string JavaScriptmedium509 accepted
• 171. create callback on message channelJavaScriptmedium496 accepted
• 164. implement Immer produce()JavaScriptmedium485 accepted
• 98. validate an IP addressJavaScriptmedium411 accepted
• 169. LRU - Chrome storage automatic evictionJavaScriptAlgorithmmedium389 accepted
• 78. convert HEX color to RGBAJavaScriptmedium356 accepted
• 143. Virtual DOM IV - JSX 1JavaScriptmedium313 accepted
• 124. calculate arithmetic expressionJavaScriptAlgorithmmedium255 accepted
• 76. implement BigInt addition with signJavaScriptmedium236 accepted
• 160. implement atob()JavaScriptmedium200 accepted
• 114. implement BigInt multiplicationJavaScriptmedium179 accepted
• 144. serialize and deserialize data types not supported in JSONJavaScriptmedium176 accepted
• 150. Virtual DOM V - JSX 2JavaScriptmedium167 accepted
• 77. implement BigInt subtraction with signJavaScriptmedium140 accepted
• 115. implement BigInt divisionJavaScriptmedium86 accepted
• 126. BigDecimal additionJavaScriptAlgorithmmedium82 accepted
• 128. BigDecimal multiplicationJavaScriptAlgorithmmedium46 accepted
• 129. BigDecimal DivisionJavaScriptAlgorithmmedium44 accepted
• 127. BigDecimal subtractionJavaScriptAlgorithmmedium39 accepted
• 175. CSS Grid Layout auto-placement algorithm - denseJavaScriptCSSmedium21 accepted