RangeError: invalid array length
The JavaScript exception "Invalid array length" occurs when specifying an array length that is either negative, a floating number or exceeds the maximum supported by the platform (i.e. when creating an Array
or ArrayBuffer
, or when setting the length
property).
The maximum allowed array length depends on the platform, browser and browser version.
For Array
the maximum length is 232-1.
For ArrayBuffer
the maximum is 231-1 (2GiB-1) on 32-bit systems.
From Firefox version 89 the maximum value of ArrayBuffer
is 233 (8GiB) on 64-bit systems.
Note: Array
and ArrayBuffer
are independent data structures (the implementation of one does not affect the other).
Message
RangeError: invalid array length (V8-based & Firefox) RangeError: Array buffer allocation failed (V8-based) RangeError: Array size is not a small enough positive integer. (Safari)
Error type
What went wrong?
An invalid array length might appear in these situations:
- Creating an
Array
orArrayBuffer
with a negative length, or setting a negative value for thelength
property. - Creating an
Array
or setting thelength
property greater than 232-1. - Creating an
ArrayBuffer
that is bigger than 232-1 (2GiB-1) on a 32-bit system, or 233 (8GiB) on a 64-bit system. - Creating an
Array
or setting thelength
property to a floating-point number. - Before Firefox 89: Creating an
ArrayBuffer
that is bigger than 232-1 (2GiB-1).
If you are creating an Array
, using the constructor, you probably want to
use the literal notation instead, as the first argument is interpreted as the length of
the Array
.
Otherwise, you might want to clamp the length before setting the length property, or using it as argument of the constructor.
Examples
Invalid cases
js
new Array(Math.pow(2, 40));
new Array(-1);
new ArrayBuffer(Math.pow(2, 32)); // 32-bit system
new ArrayBuffer(-1);
const a = [];
a.length = a.length - 1; // set the length property to -1
const b = new Array(Math.pow(2, 32) - 1);
b.length = b.length + 1; // set the length property to 2^32
b.length = 2.5; // set the length property to a floating-point number
const c = new Array(2.5); // pass a floating-point number
Valid cases
js
[Math.pow(2, 40)]; // [ 1099511627776 ]
[-1]; // [ -1 ]
new ArrayBuffer(Math.pow(2, 32) - 1);
new ArrayBuffer(Math.pow(2, 33)); // 64-bit systems after Firefox 89
new ArrayBuffer(0);
const a = [];
a.length = Math.max(0, a.length - 1);
const b = new Array(Math.pow(2, 32) - 1);
b.length = Math.min(0xffffffff, b.length + 1);
// 0xffffffff is the hexadecimal notation for 2^32 - 1
// which can also be written as (-1 >>> 0)
b.length = 3;
const c = new Array(3);