BFE
.dev
buy us
a coffee
EN
Practice
Explore
EN
JavaScript Quizzes
Test your knowledge of JavaScript the language itself.
Sort
Difficulty
Solved status
Sort: most tried
tag: JavaScript
tag: Promise
1. Promise order
JavaScript
Promise
easy
15368 tried
3. Promise then callbacks
JavaScript
Promise
easy
8025 tried
4. Promise then callbacks II
JavaScript
Promise
easy
7325 tried
2. Promise executor
JavaScript
Promise
easy
7171 tried
5. scope
JavaScript
easy
6770 tried
6. Arrow Function
JavaScript
medium
5843 tried
76. const
JavaScript
hard?
5698 tried
12. arguments
JavaScript
medium
5638 tried
8. Implicit Coercion I
JavaScript
easy
5636 tried
7. Increment Operator
JavaScript
easy
5361 tried
9. null and undefined
JavaScript
medium
3831 tried
10. Equal
JavaScript
easy
3782 tried
97. `this` V
JavaScript
easy
3060 tried
93. string
JavaScript
easy
3030 tried
27. Hoisting I
JavaScript
easy
2642 tried
70. function
JavaScript
easy
2640 tried
11. Implicit Coercion II
JavaScript
easy
2613 tried
17. reduce
JavaScript
medium
2552 tried
19. `this`
JavaScript
easy
2309 tried
29. Hoisting III
JavaScript
easy
2170 tried
68. if II
JavaScript
medium
2085 tried
67. if
JavaScript
easy
2055 tried
21. Array I
JavaScript
medium
2031 tried
20. name for Function expression
JavaScript
medium
1900 tried
14. Addition vs Unary Plus
JavaScript
easy
1874 tried
13. Operator precedence
JavaScript
easy
1830 tried
113. push
JavaScript
medium
1817 tried
120. try..catch..finally
JavaScript
easy
1782 tried
86. setTimeout III
JavaScript
easy
1782 tried
28. Hoisting II
JavaScript
easy
1782 tried
117. `this` VII
JavaScript
easy
1747 tried
89. let
JavaScript
easy
1710 tried
69. undefined
JavaScript
easy
1706 tried
41. `this` III
JavaScript
easy
1685 tried
84. Array.prototype.sort()
JavaScript
medium
1677 tried
15. instanceOf
JavaScript
easy
1663 tried
23. Promise.all()
JavaScript
easy
1654 tried
38. Hoisting IV
JavaScript
easy
1623 tried
61. onClick
JavaScript
easy
1616 tried
16. parseInt
JavaScript
easy
1614 tried
88. try...catch
JavaScript
easy
1532 tried
96. comparison
JavaScript
easy
1504 tried
42. Hoisting V
JavaScript
medium
1499 tried
81. setTimeout II
JavaScript
easy
1497 tried
32. Hoisting IIII
JavaScript
easy
1485 tried
47. Promise Order II
JavaScript
easy
1473 tried
50. async await
JavaScript
easy
1412 tried
36. Promise.prototype.finally()
JavaScript
easy
1403 tried
54. setTimeout(0ms)
JavaScript
easy
1390 tried
72. Array length
JavaScript
easy
1387 tried
18. Promise executor II
JavaScript
easy
1374 tried
39. var
JavaScript
easy
1369 tried
114. constructor
JavaScript
easy
1365 tried
94. emoji
JavaScript
easy
1363 tried
92. NaN
JavaScript
easy
1332 tried
100. `var` vs `let`
JavaScript
easy
1302 tried
95. number format
JavaScript
easy
1298 tried
116. strict
JavaScript
easy
1283 tried
73. window name
JavaScript
medium
1231 tried
33. `this` II
JavaScript
easy
1219 tried
22. min max
JavaScript
easy
1209 tried
65. Function name
JavaScript
easy
1201 tried
43. JSON.stringify()
JavaScript
medium
1190 tried
49. `this` IV
JavaScript
easy
1150 tried
55. sparse array
JavaScript
medium
1146 tried
45. Hoisting VI
JavaScript
easy
1141 tried
123. return in Generator 2
JavaScript
easy
1069 tried
25. zero
JavaScript
easy
1066 tried
124. comma 2
JavaScript
easy
1051 tried
99. closure
JavaScript
easy
1033 tried
91. largest Array index
JavaScript
easy
1030 tried
37. push unshift
JavaScript
easy
1020 tried
63. in
JavaScript
easy
1008 tried
26. true or false
JavaScript
easy
995 tried
90. array keys
JavaScript
medium
988 tried
87. instanceOf 2
JavaScript
easy
982 tried
51. method
JavaScript
medium
977 tried
111. falsy
JavaScript
easy
969 tried
79. Equal III
JavaScript
easy
960 tried
24. Equality & Sameness
JavaScript
easy
955 tried
44. Function call
JavaScript
easy
953 tried
64. reference type
JavaScript
easy
947 tried
103. Promise Order III
JavaScript
easy
946 tried
109. isNaN()
JavaScript
easy
945 tried
98. Promise executor IV
Promise
easy
945 tried
48. Prototype
JavaScript
easy
913 tried
46. Implicit Coercion IV
JavaScript
easy
913 tried
107. `this` VI
JavaScript
easy
899 tried
105. typeof
JavaScript
easy
899 tried
115. parseInt II
JavaScript
easy
894 tried
122. Iterable
JavaScript
easy
885 tried
60. postMessage
JavaScript
easy
871 tried
30. Equal II
JavaScript
easy
837 tried
106. Promise.all() II
JavaScript
easy
831 tried
108. property key
JavaScript
easy
826 tried
83. Plus Plus
JavaScript
easy
815 tried
102. Arrow Function II
JavaScript
easy
813 tried
53. Prototype 2
JavaScript
easy
792 tried
126. Object.keys()
JavaScript
medium
783 tried
74. Typed Array length
JavaScript
easy
775 tried
77. parseInt 2
JavaScript
easy
757 tried
118. structuredClone()
JavaScript
easy
755 tried
62. MessageChannel
JavaScript
easy
740 tried
85. String.raw()
JavaScript
medium
689 tried
52. requestAnimationFrame
JavaScript
easy
676 tried
34. precedence
JavaScript
easy
670 tried
121. Generator return()
JavaScript
medium
656 tried
78. RegExp
JavaScript
RegExp
medium
641 tried
112. Symbol
JavaScript
easy
638 tried
56. to primitive
JavaScript
easy
621 tried
31. Math
JavaScript
easy
619 tried
130. async
JavaScript
easy
603 tried
35. Implicit Coercion III
JavaScript
easy
580 tried
101. Equal IV
JavaScript
easy
575 tried
110. yield
JavaScript
easy
569 tried
66. comma
JavaScript
easy
569 tried
59. override setter
JavaScript
easy
549 tried
57. non-writable
JavaScript
easy
545 tried
104. Inheritance
JavaScript
easy
543 tried
82. Proxy II
JavaScript
easy
517 tried
119. return in Generator
JavaScript
medium
512 tried
80. Proxy I
JavaScript
easy
495 tried
40. RegExp.prototype.test
JavaScript
easy
492 tried
58. inherit getter setter
JavaScript
easy
467 tried
125. try...catch...finally 2
JavaScript
medium
424 tried
71. two-way generator
JavaScript
easy
413 tried
75. meaningless calculation
JavaScript
easy
405 tried
128. setTimeout IV
JavaScript
medium
293 tried
127. JSON.stringify() II
JavaScript
medium
229 tried
131. return await
JavaScript
medium
175 tried
129. Function II
JavaScript
few challengers
64 tried