BigInt.asIntN()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2020.
BigInt.asIntN 静态方法将 BigInt 值转换为一个 -2^(width-1) 与 2^(width-1)-1 之间的有符号整数。
尝试一下
const I64_CEIL = 2n ** 63n; console.log(BigInt.asIntN(64, I64_CEIL - 1n)); // 9223372036854775807n (2n ** 64n - 1n, the maximum non-wrapping value) console.log(BigInt.asIntN(64, I64_CEIL)); // -9223372036854775808n (wraps to min value) console.log(BigInt.asIntN(64, I64_CEIL + 1n)); // -9223372036854775807n (min value + 1n) console.log(BigInt.asIntN(64, I64_CEIL * 2n)); // 0n (wrapped around to zero) console.log(BigInt.asIntN(64, -I64_CEIL * -42n)); // 0n (also wraps on negative multiples) 语法
BigInt.asIntN(width, bigint);
参数
返回值
bigint 模 (modulo) 2^width 作为有符号整数的值。
示例
保持在 64 位范围内
BigInt.asIntN() 方法对于保持在 64 位 (64-bit) 算数范围内非常有用。
js
const max = 2n ** (64n - 1n) - 1n; BigInt.asIntN(64, max); // ↪ 9223372036854775807n BigInt.asIntN(64, max + 1n); // ↪ -9223372036854775808n // negative because of overflow 规范
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-bigint.asintn |