RangeError: invalid array length

訊息

RangeError: Array length must be a finite positive integer (Edge)
RangeError: invalid array length (Firefox)
RangeError: Invalid array length (Chrome)
RangeError: Invalid array buffer length (Chrome)

錯誤類型

RangeError

哪裡錯了?

一個無效的陣列長度可能發生於以下幾種情形:

為什麼 Array 和 ArrayBuffer 的長度有限? Array 和 ArrayBuffer 的屬性以一個 32 位元的非負整數表使，因此僅能儲存 0 到 2^32 - 1 的數值。

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

無效的案例

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

有效的案例

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 是 2^32 - 1 的十六進位表示
// 也可以寫成 (-1 >>> 0)

b.length = 3;

const c = new Array(3);

參見