SyntaxError: a declaration in the head of a for-of loop can't have an initializer

SyntaxError: a declaration in the head of a for-of loop can't have an initializer (Firefox)

SyntaxError: for-of loop variable declaration may not have an initializer. (Chrome)

SyntaxError

for...of |for (var i = 0 of iterable)| for-of for

`for-of`

let iterable = [10, 20, 30];

for (let value = 50 of iterable) {
  console.log(value);
}

// SyntaxError: a declaration in the head of a for-of loop can't
// have an initializer

`for-of`

(value = 50) for-of 50

let iterable = [10, 20, 30];

for (let value of iterable) {
  value += 50;
  console.log(value);
}
// 60
// 70
// 80

for...of
for...in (SyntaxError: for-in loop head declarations may not have initializers)
for

MDN

2025716 MDN

GitHub

JavaScript
JavaScript
1. +
2. +=
3. =
4. async function
5. async function*
6. await
7. &
8. &=
9. ~
10. |
11. |=
12. ^
13. (^=)
15. ,
17. --
18. delete
20. /
21. /=
22. ==
23. **
24. **=
26. function*
27. >
28. >=
30. import.meta
  1. import.meta.resolve()
31. import()
32. in
33. ++
34. !=
35. instanceof
36. (<<)
37. <<=
38. <
39. <=
40. &&
41. &&=
42. !
43. ||
44. ||=
45. *
46. *=
47. new
48. new.target
49. null
50. ??=
51. ??
54. ?.
56. %
57. %=
58. >>
59. >>=
60. ...
61. ===
62. !==
63. -
64. -=
65. super
66. this
67. typeof
68. -
69. +
70. >>>
71. >>>=
72. void
73. yield
74. yield*