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JavaScript Coding Questions
As a Front-End developer, JavaScript is the core skill of everything
Sort
Difficulty
Solved status
Company
Sort: most tried
Difficulty: easy
1. implement curry()
JavaScript
easy
59061 tried
3. implement Array.prototype.flat()
JavaScript
easy
54733 tried
6. implement basic debounce()
JavaScript
Lodash
easy
24801 tried
19. find corresponding node in two identical DOM tree
JavaScript
easy
23161 tried
18. Improve a function
JavaScript
easy
16301 tried
176. undefined to null
JavaScript
easy
16201 tried
11. what is Composition? create a pipe()
JavaScript
easy
14338 tried
23. create a sum()
JavaScript
easy
14165 tried
17. Create a simple store for DOM element
JavaScript
easy
13657 tried
28. implement clearAllTimeout()
JavaScript
easy
13300 tried
25. Reorder array with new indexes
JavaScript
Algorithm
easy
11550 tried
167. Intersection of unsorted arrays
JavaScript
Algorithm
easy
11306 tried
159. implement promisify()
JavaScript
easy
10703 tried
15. implement a simple DOM wrapper to support method chaining like jQuery
JavaScript
easy
10520 tried
155. create a count function
JavaScript
easy
9604 tried
162. find the single integer
JavaScript
Algorithm
easy
9523 tried
154. Two-way binding
JavaScript
DOM
easy
7586 tried
148. create a counter object
JavaScript
easy
7536 tried
89. Next Right Sibling
JavaScript
DOM
easy
6894 tried
157. semver compare
JavaScript
easy
6146 tried
46. implement `_.once()`
JavaScript
Lodash
easy
5935 tried
60. create your own `new` operator
JavaScript
easy
5712 tried
91. invert a binary tree
JavaScript
Algorithm
easy
5669 tried
35. implement `Promise.race()`
JavaScript
easy
5378 tried
47. reverse a linked list
JavaScript
Algorithm
easy
5196 tried
37. implement Binary Search (unique)
JavaScript
easy
5051 tried
118. Virtual DOM II - createElement
JavaScript
easy
4848 tried
145. most frequently occurring character
JavaScript
easy
4831 tried
39. implement range()
JavaScript
easy
4732 tried
163. integer to roman numerals
JavaScript
Algorithm
easy
4618 tried
31. implement async helper - `race()`
JavaScript
easy
4541 tried
121. A number sequence
JavaScript
easy
4233 tried
120. create `isPrime()`
JavaScript
Algorithm
easy
4049 tried
97. compress a string
JavaScript
string
easy
3912 tried
138. Intersection of two sorted arrays
JavaScript
Algorithm
easy
3886 tried
38. implement `jest.spyOn()`
JavaScript
easy
3854 tried
133. roman numerals to integer
JavaScript
easy
3840 tried
140. Virtual DOM III - Functional Component
JavaScript
easy
3794 tried
81. merge sorted arrays
JavaScript
Algorithm
easy
3745 tried
48. search first index with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
3681 tried
94. implement your own `Object.create`
JavaScript
easy
3643 tried
87. longest substring with unique characters
JavaScript
Algorithm
easy
3499 tried
116. implement Object.is()
JavaScript
easy
3421 tried
102. validate string of parentheses
JavaScript
Algorithm
string
easy
3242 tried
106. Find two numbers that sum up to 0
JavaScript
Algorithm
easy
3212 tried
109. implement `Math.pow()`
JavaScript
Algorithm
easy
3210 tried
40. implement Bubble Sort
JavaScript
Algorithm
easy
3117 tried
147. Pick up stones
JavaScript
easy
3078 tried
54. flatten Thunk
JavaScript
easy
3030 tried
107. Find the largest difference
JavaScript
Algorithm
easy
2963 tried
49. search last index with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
2798 tried
105. find the first duplicate character in a string
JavaScript
string
easy
2706 tried
100. detect circle in linked list
JavaScript
Algorithm
easy
2578 tried
50. search element right before target with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
2211 tried
93. Generate Fibonacci Number with recursion
JavaScript
easy
2058 tried
62. implement BigInt addition
JavaScript
Algorithm
easy
1989 tried
51. search element right after target with Binary Search(possible duplicate array)
JavaScript
Algorithm
easy
1946 tried
42. implement Insertion Sort
JavaScript
Algorithm
easy
1759 tried
44. implement Selection Sort
JavaScript
Algorithm
easy
1608 tried
142. lit-html 1 - tagged templates
JavaScript
lit-html
easy
1445 tried
96. count "1" in binary form
JavaScript
easy
1214 tried
73. implement Observable fromEvent()
JavaScript
easy
786 tried
74. implement Observable Transformation Operators
JavaScript
easy
650 tried
141. implement btoa()
JavaScript
easy
606 tried
72. implement Observable interval()
JavaScript
easy
558 tried