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JavaScript Coding Questions
As a Front-End developer, JavaScript is the core skill of everything
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Sort: most accepted
Difficulty: easy
1. implement curry()
JavaScript
easy
21182 accepted
3. implement Array.prototype.flat()
JavaScript
easy
17226 accepted
6. implement basic debounce()
JavaScript
Lodash
easy
11723 accepted
19. find corresponding node in two identical DOM tree
JavaScript
easy
8507 accepted
11. what is Composition? create a pipe()
JavaScript
easy
6581 accepted
17. Create a simple store for DOM element
JavaScript
easy
6340 accepted
28. implement clearAllTimeout()
JavaScript
easy
5502 accepted
18. Improve a function
JavaScript
easy
5480 accepted
176. undefined to null
JavaScript
easy
4865 accepted
23. create a sum()
JavaScript
easy
4453 accepted
167. Intersection of unsorted arrays
JavaScript
Algorithm
easy
4372 accepted
162. find the single integer
JavaScript
Algorithm
easy
3933 accepted
15. implement a simple DOM wrapper to support method chaining like jQuery
JavaScript
easy
3842 accepted
25. Reorder array with new indexes
JavaScript
Algorithm
easy
3695 accepted
155. create a count function
JavaScript
easy
3478 accepted
159. implement promisify()
JavaScript
easy
3221 accepted
35. implement `Promise.race()`
JavaScript
easy
3132 accepted
148. create a counter object
JavaScript
easy
3090 accepted
154. Two-way binding
JavaScript
DOM
easy
2727 accepted
91. invert a binary tree
JavaScript
Algorithm
easy
2434 accepted
39. implement range()
JavaScript
easy
2335 accepted
89. Next Right Sibling
JavaScript
DOM
easy
2276 accepted
157. semver compare
JavaScript
easy
2183 accepted
60. create your own `new` operator
JavaScript
easy
1950 accepted
37. implement Binary Search (unique)
JavaScript
easy
1918 accepted
47. reverse a linked list
JavaScript
Algorithm
easy
1817 accepted
145. most frequently occurring character
JavaScript
easy
1812 accepted
46. implement `_.once()`
JavaScript
Lodash
easy
1787 accepted
31. implement async helper - `race()`
JavaScript
easy
1753 accepted
163. integer to roman numerals
JavaScript
Algorithm
easy
1642 accepted
133. roman numerals to integer
JavaScript
easy
1601 accepted
118. Virtual DOM II - createElement
JavaScript
easy
1570 accepted
40. implement Bubble Sort
JavaScript
Algorithm
easy
1566 accepted
121. A number sequence
JavaScript
easy
1421 accepted
105. find the first duplicate character in a string
JavaScript
string
easy
1414 accepted
107. Find the largest difference
JavaScript
Algorithm
easy
1405 accepted
81. merge sorted arrays
JavaScript
Algorithm
easy
1372 accepted
138. Intersection of two sorted arrays
JavaScript
Algorithm
easy
1356 accepted
94. implement your own `Object.create`
JavaScript
easy
1348 accepted
38. implement `jest.spyOn()`
JavaScript
easy
1307 accepted
120. create `isPrime()`
JavaScript
Algorithm
easy
1287 accepted
106. Find two numbers that sum up to 0
JavaScript
Algorithm
easy
1276 accepted
102. validate string of parentheses
JavaScript
Algorithm
string
easy
1267 accepted
48. search first index with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
1202 accepted
97. compress a string
JavaScript
string
easy
1180 accepted
140. Virtual DOM III - Functional Component
JavaScript
easy
1177 accepted
87. longest substring with unique characters
JavaScript
Algorithm
easy
1166 accepted
54. flatten Thunk
JavaScript
easy
1136 accepted
109. implement `Math.pow()`
JavaScript
Algorithm
easy
1064 accepted
116. implement Object.is()
JavaScript
easy
1060 accepted
49. search last index with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
1005 accepted
93. Generate Fibonacci Number with recursion
JavaScript
easy
955 accepted
147. Pick up stones
JavaScript
easy
941 accepted
100. detect circle in linked list
JavaScript
Algorithm
easy
934 accepted
42. implement Insertion Sort
JavaScript
Algorithm
easy
929 accepted
44. implement Selection Sort
JavaScript
Algorithm
easy
795 accepted
50. search element right before target with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
793 accepted
51. search element right after target with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
724 accepted
96. count "1" in binary form
JavaScript
easy
691 accepted
62. implement BigInt addition
JavaScript
Algorithm
easy
653 accepted
142. lit-html 1 - tagged templates
JavaScript
lit-html
easy
520 accepted
72. implement Observable interval()
JavaScript
easy
395 accepted
74. implement Observable Transformation Operators
JavaScript
easy
368 accepted
73. implement Observable fromEvent()
JavaScript
easy
359 accepted
141. implement btoa()
JavaScript
easy
228 accepted