范围错误：数组长度无效

当指定的数组长度为负数、浮点数或超出平台支持的最大值时（即创建 Array 或 ArrayBuffer 时，或设置 length 属性时），会发生 JavaScript 异常 "数组长度无效"。

¥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).

允许的最大数组长度取决于平台、浏览器和浏览器版本。对于 Array，最大长度为 232-1。对于 ArrayBuffer，32 位系统上的最大值为 231-1 (2GiB-1)。从 Firefox 版本 89 开始，64 位系统上 ArrayBuffer 的最大值为 233 (8GiB)。

¥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.

注意：Array 和 ArrayBuffer 是独立的数据结构（其中一个的实现不影响另一个）。

¥Note: Array and ArrayBuffer are independent data structures (the implementation of one does not affect the other).

信息

¥Message

RangeError: invalid array length (V8-based & Firefox)
RangeError: Array size is not a small enough positive integer. (Safari)

RangeError: Invalid array buffer length (V8-based)
RangeError: length too large (Safari)

错误类型

¥Error type

RangeError

什么地方出了错？

¥What went wrong?

当尝试生成具有无效长度的 Array 或 ArrayBuffer 时，可能会出现错误，其中包括：

¥The error might appear when attempting to produce an Array or ArrayBuffer with an invalid length, which includes:

  • 负长度，通过构造函数或设置 length 属性。
  • 非整数长度，通过构造函数或设置 length 属性。（ArrayBuffer 构造函数将长度强制为整数，但 Array 构造函数不会。）
  • 超过平台支持的最大长度。对于数组，最大长度为 232-1。对于 ArrayBuffer，最大长度在 32 位系统上为 231-1 (2GiB-1)，在 64 位系统上为 233 (8GiB)。这可以通过构造函数、设置 length 属性或隐式设置长度属性的数组方法（例如 push 和 concat）来实现。

如果你使用构造函数创建 Array，则可能希望改用文字符号，因为第一个参数被解释为 Array 的长度。否则，你可能需要在设置 length 属性之前限制长度，或将其用作构造函数的参数。

¥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.

示例

¥Examples

无效案例

¥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

// Concurrent modification that accidentally grows the array infinitely
const arr = [1, 2, 3];
for (const e of arr) {
  arr.push(e * 10);
}

有效案例

¥Valid cases

js
[Math.pow(2, 40)]; // [ 1099511627776 ]
[-1]; // [ -1 ]
new ArrayBuffer(Math.pow(2, 31) - 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);

// Because array methods save the length before iterating, it is safe to grow
// the array during iteration
const arr = [1, 2, 3];
arr.forEach((e) => arr.push(e * 10));

也可以看看

¥See also