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
哪裡錯了?
一個無效的陣列長度可能發生於以下幾種情形:
- 建立了一個長度為負或大於等於 2^32 的
Array
或ArrayBuffer
- 將
Array.length
屬性設為負值或大於等於 2^32
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);